Blog
August 28, 2025
Blog
August 28, 2025
Blog
August 28, 2025
Add custom fonts in Klaviyo fast. Use Google, Adobe or hosted files, set safe fallbacks for Gmail, and test on mobile to ship readable, on-brand emails.
Custom fonts make your Klaviyo emails look like your brand, not a template. Want headlines that stay on-brand everywhere, even when Gmail ignores web fonts?
Use Klaviyo’s font tools to add Google Fonts, Adobe Fonts via a Typekit CSS URL, or a self-hosted font, then apply it with safe fallbacks so your design holds up when an inbox does not load web fonts.
What This Guide Covers
Adding fonts in Klaviyo: Google, Adobe (Typekit) and hosted URLs
Styling globally and per block, with reliable fallback stacks
Client support basics and what to expect in Gmail
Performance, accessibility and sizing guidelines
Testing workflows and quick troubleshooting
Strategic branding do’s and don’ts for consistent typography
Remember that many inboxes, including Gmail and Yahoo, ignore web fonts, so fallbacks are essential.
Why Custom Fonts Matter in Klaviyo
Typography influences how quickly people scan, trust and act. Using your brand font can lift perceived quality and keep your lifecycle messages on-brand. Because many inboxes don’t load web fonts, plan your typography so a close web-safe fallback still feels on-brand.
Where fonts help most
Brand scaffolding emails such as welcome, about and post-purchase content.
High-impact launches and seasonal pushes where visual distinctiveness matters.
Some major inboxes (e.g., Gmail, Yahoo) will fall back to system fonts, so design headings and body copy that read well in both your brand font and the fallback stack.
Editorial notes or founder letters that rely on tone and hierarchy.
Proof points you can rely on
Klaviyo supports Google Fonts, Adobe Fonts (Typekit CSS), and imported self-hosted fonts directly in the editor, and prompts you to set a fallback so designs hold up when a client doesn’t load the web font. Klaviyo Help Center
Gmail generally does not load web fonts (with an exception for Roboto), so a well-matched fallback preserves legibility and layout across your list’s top clients.
For accessibility, use clear hierarchy and larger, readable sizes (Litmus recommends at least 14 px for body text) — see Litmus’ accessibility guide.
Step-by-Step Setup for Klaviyo Custom Fonts
You can add Google Fonts, Adobe Fonts or a self-hosted font directly in Klaviyo’s template editor, then apply it with a safe fallback so designs hold up in every inbox.
Detailed Steps:
1. Open or create an email Template, then open a Text block or use the Content & Styles tab to manage fonts.
2. In the font dropdown, click Add Font, then choose Google Font, Adobe Font, or Import Font as your source.
3. Google Font: search for the font name, choose a close fallback (for clients that do not load web fonts), then select Add Font.
Source: Klaviyo
4. Adobe Font: paste your kit’s CSS address in the form https://use.typekit.com/XXXXX.css, choose a fallback, then click Add Font; this requires an active Adobe Fonts subscription.
5. Import Font: host the file publicly, enable CORS by returning the header Access-Control-Allow-Origin: *, paste the font URL, set name, weight and style, then click Add Font.
6. Manage or remove fonts later at Content → Images & Brand → Fonts using the three-dot menu; Adobe variants are defined by your kit CSS and cannot be edited inside Klaviyo.
7. After adding a font, it appears in your account’s Fonts library and can be used across email templates and sign-up forms.
8. Use Preview & test → Send test to check rendering on iOS, Android and desktop, or run Inbox testing for multi-client previews.
Apply Your Font in Email Styles
After adding a font, apply it at the template level for consistency or at the block/text level for precision — Klaviyo’s editor lets you set fonts in Template Styles, Block Styles, and inside Text blocks.
Where to apply:
Template styles: Open the Styles tab (top of the editor) to set global typography for headings and body so every block inherits your brand font by default.
Block styles: Select any block and use its Styles panel to override the global font for that block only.
Specific text: Click a Text block, highlight the copy, and pick your custom font from the dropdown to style just that selection.
You can apply custom fonts not only to text blocks but also to button blocks, product blocks, and other blocks containing text via the font dropdown.
Fallbacks that protect you
Always choose a web-safe fallback when you add a custom font; inboxes that don’t load web fonts (e.g., Gmail/Yahoo) will show this fallback.
Example stack:
font-family: 'Your Brand Font', Arial, Helvetica, sans-serif;(pick a fallback with similar proportions) — rationale and client list.
Pro tip: Build one master template and/or save common sections as Universal content so your font sizes and hierarchy stay consistent across campaigns.
Understand Email Client Limitations
Not every inbox loads web fonts, so plan where your brand font renders and where a fallback appears — see Klaviyo’s overview of fonts in email and client support.
Broad support list
Web fonts commonly render in Apple Mail, iOS Mail, Android mail apps (with some older-version caveats), Samsung Mail, and Outlook for Mac.
Major exceptions
Gmail and Yahoo generally don’t load web fonts; Gmail’s notable exception is Roboto, so expect your fallback to display in those inboxes.
What this means
Set a clear fallback stack, e.g.
font-family: 'Your Brand Font', Arial, Helvetica, sans-serif;— pick a fallback with similar proportions so spacing and line breaks remain stable (Klaviyo guidance).Use your custom font for headlines and keep body copy web-safe when your audience skews to Gmail/Yahoo; this preserves legibility while keeping the brand feel.
To monitor performance by inbox provider over time, review account-level signals in Klaviyo’s Deliverability hub and adjust your fallback stack or typography sizes if needed.
Optimise for Mobile and Load Time
Fonts should never slow the scroll: keep payloads lean and sizes readable so emails load fast and stay accessible on mobile.
Best practices
Limit font weights/variants to one or two, and avoid extra italics to reduce requests and keep messages fast.
When importing a font, host efficiently for small files. Klaviyo loads the font by URL, so efficient hosting matters.
Respect readability: use at least 14 px for body text with generous line height (~1.5), and consider going larger on mobile.
Use a master template and Universal content (saved headers/footers/sections) so spacing, sizes and fonts stay consistent across devices.
Where to avoid over-engineering
Use your brand font for headlines and CTAs, and keep body copy web-safe when your audience skews to Gmail/Yahoo.
Don’t stack multiple custom families or heavy CSS; keep one primary family with a clear fallback stack (e.g.,
font-family: 'Brand Font', Arial, Helvetica, sans-serif;).sd ;/
Test Your Font Integration
Validate before you send: preview in Klaviyo, run Inbox testing for multi-client renders, and check dark mode so your font + fallback look right everywhere.
Your testing checklist
Use Preview & test → Send test to send yourself and colleagues a live preview on iOS, Android and desktop.
Expand coverage with Inbox testing inside Klaviyo to preview on many clients without leaving your account.
For deep cross-client previews, use Litmus or Email on Acid (Sinch).
Check dark mode legibility, line height and fallback behaviour.
Design for dark mode differences using Litmus’ Dark Mode Email guide to handle image/logo swaps, colour inversions and
prefers-color-schemetesting.If fonts drive the concept, set up a campaign A/B test (custom-font headline vs web-safe) and review results in campaign analytics to see impact by audience segments and behaviours.
For a step-by-step experimentation plan, use our Klaviyo Split Testing playbook.
Troubleshooting Font Issues
If a font does not appear, first determine whether it is a source issue, a client support limit or a fallback choice.
Quick fixes
Doesn’t render at all: confirm you selected the correct source (Google, Adobe, Import), that the URL is public, and that imported fonts are served with
Access-Control-Allow-Origin: *. You cannot upload font files to Klaviyo; you must host and Import Font via URL.Looks different in Gmail: expected. Gmail generally does not load web fonts (Roboto is a notable exception), so your fallback will display. Ensure a close web-safe fallback is set.
Variant missing: add weights in Content → Images & Brand → Fonts. For Adobe Fonts, variants are defined in your kit CSS; update the kit if you need different weights.
Buttons and product blocks: yes. Open the block, go to Styles, and select your custom font so CTAs and product content match your template styles.
Preview mismatch: send a Preview & test → Send test, then run Inbox testing for multi-client previews.
Name or family mismatch: the
font-familylabel you select in Klaviyo must match the added font name and variant. Re-select the intended weight (for example Semibold vs Regular) in the block or template Styles.Self-hosted font blocked by policy: if the font is served from a domain that disallows cross-origin requests, the file will not load. Enable CORS and retest.
Strategic Tips for Font-Led Branding
Treat fonts as part of your brand system, not decoration: plan type pairs, set reliable fallbacks, and keep copy readable on mobile using proven accessibility guidance from Klaviyo and Litmus.
Practical moves
Mirror your website pairings so emails feel native to your brand.
Use bold or semibold for headings and regular for body; keep sizes scannable and consistent across templates.
Limit yourself to two font families to avoid visual noise and slower loads.
Follow the sizing guidance and check contrast before you ship.
Choose a fallback with similar proportions to your brand font so spacing and line breaks remain stable where web fonts do not load.
Check colour contrast for legibility, aiming for at least 4.5:1 for body text.
Use decorative or script faces only for short headlines and keep body copy in a highly readable family.
Standardise hierarchy by saving a master template and shared sections with your chosen fonts.
Related reads from Titan:
Align tone and typography choices with Klaviyo Brand Voice: 7 Steps to Stay Consistent and Convert More.
Pair strong type hierarchy with clickable layouts using Klaviyo Product Block: 6 Easy Ways to Drive Clicks.
FAQs
1. What if I want custom fonts in sign-up forms too?
You can use custom fonts in forms. Add the font to Content → Images & brand → Fonts, then apply it in your form styles. See Custom fonts in sign-up forms and Klaviyo-hosted fonts.
2. Do Adobe Fonts require a subscription or special URL?
Yes. An active Adobe Fonts plan is required, and you paste the kit CSS URL that looks like
https://use.typekit.com/xxxxx.css.
3. Can I upload a font file to Klaviyo?
No. Host the font yourself or use Google Fonts or Adobe Fonts, then Import Font in Klaviyo.
4. Will Gmail show my custom font?
Gmail generally does not load web fonts. A notable exception is Roboto. Plan a close web-safe fallback.
5. Do buttons and product blocks respect custom fonts?
Yes. Set the font in the template Styles or each block’s Styles so CTAs and product blocks inherit it.
Conclusion
Custom fonts help your emails look like your brand. Some inboxes will not load them, so you need a good fallback. Add your fonts the right way in Klaviyo, apply them to templates and blocks, and test on real devices. Keep body text large and easy to read. Use only a few weights so emails load fast.
With these steps, your designs stay consistent and clear, and your readers can scan and act quickly. Make your typography a signature your customers recognise at a glance.
Key Takeaways
Three ways to add: Google, Adobe or hosted via Import Font, saved for reuse.
Plan fallbacks: Many inboxes show the fallback, especially Gmail and Yahoo.
Apply in styles: Set fonts in template styles and in each block, including buttons and product blocks.
Test widely: Use Inbox testing and Preview & test to check your top clients before you send.
Stay readable: Use at least 14 px body and about 1.5 line height for easy scanning on mobile.
Host correctly: For imported fonts, enable CORS on your host so fonts load reliably.
Tired of default fonts making your designs feel flat?
Make your message stand out in the inbox with visually distinct, mobile-optimised custom fonts that drive conversions. Click here to book your free Klaviyo audit to unlock design-led performance improvements.
Custom fonts make your Klaviyo emails look like your brand, not a template. Want headlines that stay on-brand everywhere, even when Gmail ignores web fonts?
Use Klaviyo’s font tools to add Google Fonts, Adobe Fonts via a Typekit CSS URL, or a self-hosted font, then apply it with safe fallbacks so your design holds up when an inbox does not load web fonts.
What This Guide Covers
Adding fonts in Klaviyo: Google, Adobe (Typekit) and hosted URLs
Styling globally and per block, with reliable fallback stacks
Client support basics and what to expect in Gmail
Performance, accessibility and sizing guidelines
Testing workflows and quick troubleshooting
Strategic branding do’s and don’ts for consistent typography
Remember that many inboxes, including Gmail and Yahoo, ignore web fonts, so fallbacks are essential.
Why Custom Fonts Matter in Klaviyo
Typography influences how quickly people scan, trust and act. Using your brand font can lift perceived quality and keep your lifecycle messages on-brand. Because many inboxes don’t load web fonts, plan your typography so a close web-safe fallback still feels on-brand.
Where fonts help most
Brand scaffolding emails such as welcome, about and post-purchase content.
High-impact launches and seasonal pushes where visual distinctiveness matters.
Some major inboxes (e.g., Gmail, Yahoo) will fall back to system fonts, so design headings and body copy that read well in both your brand font and the fallback stack.
Editorial notes or founder letters that rely on tone and hierarchy.
Proof points you can rely on
Klaviyo supports Google Fonts, Adobe Fonts (Typekit CSS), and imported self-hosted fonts directly in the editor, and prompts you to set a fallback so designs hold up when a client doesn’t load the web font. Klaviyo Help Center
Gmail generally does not load web fonts (with an exception for Roboto), so a well-matched fallback preserves legibility and layout across your list’s top clients.
For accessibility, use clear hierarchy and larger, readable sizes (Litmus recommends at least 14 px for body text) — see Litmus’ accessibility guide.
Step-by-Step Setup for Klaviyo Custom Fonts
You can add Google Fonts, Adobe Fonts or a self-hosted font directly in Klaviyo’s template editor, then apply it with a safe fallback so designs hold up in every inbox.
Detailed Steps:
1. Open or create an email Template, then open a Text block or use the Content & Styles tab to manage fonts.
2. In the font dropdown, click Add Font, then choose Google Font, Adobe Font, or Import Font as your source.
3. Google Font: search for the font name, choose a close fallback (for clients that do not load web fonts), then select Add Font.
Source: Klaviyo
4. Adobe Font: paste your kit’s CSS address in the form https://use.typekit.com/XXXXX.css, choose a fallback, then click Add Font; this requires an active Adobe Fonts subscription.
5. Import Font: host the file publicly, enable CORS by returning the header Access-Control-Allow-Origin: *, paste the font URL, set name, weight and style, then click Add Font.
6. Manage or remove fonts later at Content → Images & Brand → Fonts using the three-dot menu; Adobe variants are defined by your kit CSS and cannot be edited inside Klaviyo.
7. After adding a font, it appears in your account’s Fonts library and can be used across email templates and sign-up forms.
8. Use Preview & test → Send test to check rendering on iOS, Android and desktop, or run Inbox testing for multi-client previews.
Apply Your Font in Email Styles
After adding a font, apply it at the template level for consistency or at the block/text level for precision — Klaviyo’s editor lets you set fonts in Template Styles, Block Styles, and inside Text blocks.
Where to apply:
Template styles: Open the Styles tab (top of the editor) to set global typography for headings and body so every block inherits your brand font by default.
Block styles: Select any block and use its Styles panel to override the global font for that block only.
Specific text: Click a Text block, highlight the copy, and pick your custom font from the dropdown to style just that selection.
You can apply custom fonts not only to text blocks but also to button blocks, product blocks, and other blocks containing text via the font dropdown.
Fallbacks that protect you
Always choose a web-safe fallback when you add a custom font; inboxes that don’t load web fonts (e.g., Gmail/Yahoo) will show this fallback.
Example stack:
font-family: 'Your Brand Font', Arial, Helvetica, sans-serif;(pick a fallback with similar proportions) — rationale and client list.
Pro tip: Build one master template and/or save common sections as Universal content so your font sizes and hierarchy stay consistent across campaigns.
Understand Email Client Limitations
Not every inbox loads web fonts, so plan where your brand font renders and where a fallback appears — see Klaviyo’s overview of fonts in email and client support.
Broad support list
Web fonts commonly render in Apple Mail, iOS Mail, Android mail apps (with some older-version caveats), Samsung Mail, and Outlook for Mac.
Major exceptions
Gmail and Yahoo generally don’t load web fonts; Gmail’s notable exception is Roboto, so expect your fallback to display in those inboxes.
What this means
Set a clear fallback stack, e.g.
font-family: 'Your Brand Font', Arial, Helvetica, sans-serif;— pick a fallback with similar proportions so spacing and line breaks remain stable (Klaviyo guidance).Use your custom font for headlines and keep body copy web-safe when your audience skews to Gmail/Yahoo; this preserves legibility while keeping the brand feel.
To monitor performance by inbox provider over time, review account-level signals in Klaviyo’s Deliverability hub and adjust your fallback stack or typography sizes if needed.
Optimise for Mobile and Load Time
Fonts should never slow the scroll: keep payloads lean and sizes readable so emails load fast and stay accessible on mobile.
Best practices
Limit font weights/variants to one or two, and avoid extra italics to reduce requests and keep messages fast.
When importing a font, host efficiently for small files. Klaviyo loads the font by URL, so efficient hosting matters.
Respect readability: use at least 14 px for body text with generous line height (~1.5), and consider going larger on mobile.
Use a master template and Universal content (saved headers/footers/sections) so spacing, sizes and fonts stay consistent across devices.
Where to avoid over-engineering
Use your brand font for headlines and CTAs, and keep body copy web-safe when your audience skews to Gmail/Yahoo.
Don’t stack multiple custom families or heavy CSS; keep one primary family with a clear fallback stack (e.g.,
font-family: 'Brand Font', Arial, Helvetica, sans-serif;).sd ;/
Test Your Font Integration
Validate before you send: preview in Klaviyo, run Inbox testing for multi-client renders, and check dark mode so your font + fallback look right everywhere.
Your testing checklist
Use Preview & test → Send test to send yourself and colleagues a live preview on iOS, Android and desktop.
Expand coverage with Inbox testing inside Klaviyo to preview on many clients without leaving your account.
For deep cross-client previews, use Litmus or Email on Acid (Sinch).
Check dark mode legibility, line height and fallback behaviour.
Design for dark mode differences using Litmus’ Dark Mode Email guide to handle image/logo swaps, colour inversions and
prefers-color-schemetesting.If fonts drive the concept, set up a campaign A/B test (custom-font headline vs web-safe) and review results in campaign analytics to see impact by audience segments and behaviours.
For a step-by-step experimentation plan, use our Klaviyo Split Testing playbook.
Troubleshooting Font Issues
If a font does not appear, first determine whether it is a source issue, a client support limit or a fallback choice.
Quick fixes
Doesn’t render at all: confirm you selected the correct source (Google, Adobe, Import), that the URL is public, and that imported fonts are served with
Access-Control-Allow-Origin: *. You cannot upload font files to Klaviyo; you must host and Import Font via URL.Looks different in Gmail: expected. Gmail generally does not load web fonts (Roboto is a notable exception), so your fallback will display. Ensure a close web-safe fallback is set.
Variant missing: add weights in Content → Images & Brand → Fonts. For Adobe Fonts, variants are defined in your kit CSS; update the kit if you need different weights.
Buttons and product blocks: yes. Open the block, go to Styles, and select your custom font so CTAs and product content match your template styles.
Preview mismatch: send a Preview & test → Send test, then run Inbox testing for multi-client previews.
Name or family mismatch: the
font-familylabel you select in Klaviyo must match the added font name and variant. Re-select the intended weight (for example Semibold vs Regular) in the block or template Styles.Self-hosted font blocked by policy: if the font is served from a domain that disallows cross-origin requests, the file will not load. Enable CORS and retest.
Strategic Tips for Font-Led Branding
Treat fonts as part of your brand system, not decoration: plan type pairs, set reliable fallbacks, and keep copy readable on mobile using proven accessibility guidance from Klaviyo and Litmus.
Practical moves
Mirror your website pairings so emails feel native to your brand.
Use bold or semibold for headings and regular for body; keep sizes scannable and consistent across templates.
Limit yourself to two font families to avoid visual noise and slower loads.
Follow the sizing guidance and check contrast before you ship.
Choose a fallback with similar proportions to your brand font so spacing and line breaks remain stable where web fonts do not load.
Check colour contrast for legibility, aiming for at least 4.5:1 for body text.
Use decorative or script faces only for short headlines and keep body copy in a highly readable family.
Standardise hierarchy by saving a master template and shared sections with your chosen fonts.
Related reads from Titan:
Align tone and typography choices with Klaviyo Brand Voice: 7 Steps to Stay Consistent and Convert More.
Pair strong type hierarchy with clickable layouts using Klaviyo Product Block: 6 Easy Ways to Drive Clicks.
FAQs
1. What if I want custom fonts in sign-up forms too?
You can use custom fonts in forms. Add the font to Content → Images & brand → Fonts, then apply it in your form styles. See Custom fonts in sign-up forms and Klaviyo-hosted fonts.
2. Do Adobe Fonts require a subscription or special URL?
Yes. An active Adobe Fonts plan is required, and you paste the kit CSS URL that looks like
https://use.typekit.com/xxxxx.css.
3. Can I upload a font file to Klaviyo?
No. Host the font yourself or use Google Fonts or Adobe Fonts, then Import Font in Klaviyo.
4. Will Gmail show my custom font?
Gmail generally does not load web fonts. A notable exception is Roboto. Plan a close web-safe fallback.
5. Do buttons and product blocks respect custom fonts?
Yes. Set the font in the template Styles or each block’s Styles so CTAs and product blocks inherit it.
Conclusion
Custom fonts help your emails look like your brand. Some inboxes will not load them, so you need a good fallback. Add your fonts the right way in Klaviyo, apply them to templates and blocks, and test on real devices. Keep body text large and easy to read. Use only a few weights so emails load fast.
With these steps, your designs stay consistent and clear, and your readers can scan and act quickly. Make your typography a signature your customers recognise at a glance.
Key Takeaways
Three ways to add: Google, Adobe or hosted via Import Font, saved for reuse.
Plan fallbacks: Many inboxes show the fallback, especially Gmail and Yahoo.
Apply in styles: Set fonts in template styles and in each block, including buttons and product blocks.
Test widely: Use Inbox testing and Preview & test to check your top clients before you send.
Stay readable: Use at least 14 px body and about 1.5 line height for easy scanning on mobile.
Host correctly: For imported fonts, enable CORS on your host so fonts load reliably.
Tired of default fonts making your designs feel flat?
Make your message stand out in the inbox with visually distinct, mobile-optimised custom fonts that drive conversions. Click here to book your free Klaviyo audit to unlock design-led performance improvements.
Add custom fonts in Klaviyo fast. Use Google, Adobe or hosted files, set safe fallbacks for Gmail, and test on mobile to ship readable, on-brand emails.
Custom fonts make your Klaviyo emails look like your brand, not a template. Want headlines that stay on-brand everywhere, even when Gmail ignores web fonts?
Use Klaviyo’s font tools to add Google Fonts, Adobe Fonts via a Typekit CSS URL, or a self-hosted font, then apply it with safe fallbacks so your design holds up when an inbox does not load web fonts.
What This Guide Covers
Adding fonts in Klaviyo: Google, Adobe (Typekit) and hosted URLs
Styling globally and per block, with reliable fallback stacks
Client support basics and what to expect in Gmail
Performance, accessibility and sizing guidelines
Testing workflows and quick troubleshooting
Strategic branding do’s and don’ts for consistent typography
Remember that many inboxes, including Gmail and Yahoo, ignore web fonts, so fallbacks are essential.
Why Custom Fonts Matter in Klaviyo
Typography influences how quickly people scan, trust and act. Using your brand font can lift perceived quality and keep your lifecycle messages on-brand. Because many inboxes don’t load web fonts, plan your typography so a close web-safe fallback still feels on-brand.
Where fonts help most
Brand scaffolding emails such as welcome, about and post-purchase content.
High-impact launches and seasonal pushes where visual distinctiveness matters.
Some major inboxes (e.g., Gmail, Yahoo) will fall back to system fonts, so design headings and body copy that read well in both your brand font and the fallback stack.
Editorial notes or founder letters that rely on tone and hierarchy.
Proof points you can rely on
Klaviyo supports Google Fonts, Adobe Fonts (Typekit CSS), and imported self-hosted fonts directly in the editor, and prompts you to set a fallback so designs hold up when a client doesn’t load the web font. Klaviyo Help Center
Gmail generally does not load web fonts (with an exception for Roboto), so a well-matched fallback preserves legibility and layout across your list’s top clients.
For accessibility, use clear hierarchy and larger, readable sizes (Litmus recommends at least 14 px for body text) — see Litmus’ accessibility guide.
Step-by-Step Setup for Klaviyo Custom Fonts
You can add Google Fonts, Adobe Fonts or a self-hosted font directly in Klaviyo’s template editor, then apply it with a safe fallback so designs hold up in every inbox.
Detailed Steps:
1. Open or create an email Template, then open a Text block or use the Content & Styles tab to manage fonts.
2. In the font dropdown, click Add Font, then choose Google Font, Adobe Font, or Import Font as your source.
3. Google Font: search for the font name, choose a close fallback (for clients that do not load web fonts), then select Add Font.
Source: Klaviyo
4. Adobe Font: paste your kit’s CSS address in the form https://use.typekit.com/XXXXX.css, choose a fallback, then click Add Font; this requires an active Adobe Fonts subscription.
5. Import Font: host the file publicly, enable CORS by returning the header Access-Control-Allow-Origin: *, paste the font URL, set name, weight and style, then click Add Font.
6. Manage or remove fonts later at Content → Images & Brand → Fonts using the three-dot menu; Adobe variants are defined by your kit CSS and cannot be edited inside Klaviyo.
7. After adding a font, it appears in your account’s Fonts library and can be used across email templates and sign-up forms.
8. Use Preview & test → Send test to check rendering on iOS, Android and desktop, or run Inbox testing for multi-client previews.
Apply Your Font in Email Styles
After adding a font, apply it at the template level for consistency or at the block/text level for precision — Klaviyo’s editor lets you set fonts in Template Styles, Block Styles, and inside Text blocks.
Where to apply:
Template styles: Open the Styles tab (top of the editor) to set global typography for headings and body so every block inherits your brand font by default.
Block styles: Select any block and use its Styles panel to override the global font for that block only.
Specific text: Click a Text block, highlight the copy, and pick your custom font from the dropdown to style just that selection.
You can apply custom fonts not only to text blocks but also to button blocks, product blocks, and other blocks containing text via the font dropdown.
Fallbacks that protect you
Always choose a web-safe fallback when you add a custom font; inboxes that don’t load web fonts (e.g., Gmail/Yahoo) will show this fallback.
Example stack:
font-family: 'Your Brand Font', Arial, Helvetica, sans-serif;(pick a fallback with similar proportions) — rationale and client list.
Pro tip: Build one master template and/or save common sections as Universal content so your font sizes and hierarchy stay consistent across campaigns.
Understand Email Client Limitations
Not every inbox loads web fonts, so plan where your brand font renders and where a fallback appears — see Klaviyo’s overview of fonts in email and client support.
Broad support list
Web fonts commonly render in Apple Mail, iOS Mail, Android mail apps (with some older-version caveats), Samsung Mail, and Outlook for Mac.
Major exceptions
Gmail and Yahoo generally don’t load web fonts; Gmail’s notable exception is Roboto, so expect your fallback to display in those inboxes.
What this means
Set a clear fallback stack, e.g.
font-family: 'Your Brand Font', Arial, Helvetica, sans-serif;— pick a fallback with similar proportions so spacing and line breaks remain stable (Klaviyo guidance).Use your custom font for headlines and keep body copy web-safe when your audience skews to Gmail/Yahoo; this preserves legibility while keeping the brand feel.
To monitor performance by inbox provider over time, review account-level signals in Klaviyo’s Deliverability hub and adjust your fallback stack or typography sizes if needed.
Optimise for Mobile and Load Time
Fonts should never slow the scroll: keep payloads lean and sizes readable so emails load fast and stay accessible on mobile.
Best practices
Limit font weights/variants to one or two, and avoid extra italics to reduce requests and keep messages fast.
When importing a font, host efficiently for small files. Klaviyo loads the font by URL, so efficient hosting matters.
Respect readability: use at least 14 px for body text with generous line height (~1.5), and consider going larger on mobile.
Use a master template and Universal content (saved headers/footers/sections) so spacing, sizes and fonts stay consistent across devices.
Where to avoid over-engineering
Use your brand font for headlines and CTAs, and keep body copy web-safe when your audience skews to Gmail/Yahoo.
Don’t stack multiple custom families or heavy CSS; keep one primary family with a clear fallback stack (e.g.,
font-family: 'Brand Font', Arial, Helvetica, sans-serif;).sd ;/
Test Your Font Integration
Validate before you send: preview in Klaviyo, run Inbox testing for multi-client renders, and check dark mode so your font + fallback look right everywhere.
Your testing checklist
Use Preview & test → Send test to send yourself and colleagues a live preview on iOS, Android and desktop.
Expand coverage with Inbox testing inside Klaviyo to preview on many clients without leaving your account.
For deep cross-client previews, use Litmus or Email on Acid (Sinch).
Check dark mode legibility, line height and fallback behaviour.
Design for dark mode differences using Litmus’ Dark Mode Email guide to handle image/logo swaps, colour inversions and
prefers-color-schemetesting.If fonts drive the concept, set up a campaign A/B test (custom-font headline vs web-safe) and review results in campaign analytics to see impact by audience segments and behaviours.
For a step-by-step experimentation plan, use our Klaviyo Split Testing playbook.
Troubleshooting Font Issues
If a font does not appear, first determine whether it is a source issue, a client support limit or a fallback choice.
Quick fixes
Doesn’t render at all: confirm you selected the correct source (Google, Adobe, Import), that the URL is public, and that imported fonts are served with
Access-Control-Allow-Origin: *. You cannot upload font files to Klaviyo; you must host and Import Font via URL.Looks different in Gmail: expected. Gmail generally does not load web fonts (Roboto is a notable exception), so your fallback will display. Ensure a close web-safe fallback is set.
Variant missing: add weights in Content → Images & Brand → Fonts. For Adobe Fonts, variants are defined in your kit CSS; update the kit if you need different weights.
Buttons and product blocks: yes. Open the block, go to Styles, and select your custom font so CTAs and product content match your template styles.
Preview mismatch: send a Preview & test → Send test, then run Inbox testing for multi-client previews.
Name or family mismatch: the
font-familylabel you select in Klaviyo must match the added font name and variant. Re-select the intended weight (for example Semibold vs Regular) in the block or template Styles.Self-hosted font blocked by policy: if the font is served from a domain that disallows cross-origin requests, the file will not load. Enable CORS and retest.
Strategic Tips for Font-Led Branding
Treat fonts as part of your brand system, not decoration: plan type pairs, set reliable fallbacks, and keep copy readable on mobile using proven accessibility guidance from Klaviyo and Litmus.
Practical moves
Mirror your website pairings so emails feel native to your brand.
Use bold or semibold for headings and regular for body; keep sizes scannable and consistent across templates.
Limit yourself to two font families to avoid visual noise and slower loads.
Follow the sizing guidance and check contrast before you ship.
Choose a fallback with similar proportions to your brand font so spacing and line breaks remain stable where web fonts do not load.
Check colour contrast for legibility, aiming for at least 4.5:1 for body text.
Use decorative or script faces only for short headlines and keep body copy in a highly readable family.
Standardise hierarchy by saving a master template and shared sections with your chosen fonts.
Related reads from Titan:
Align tone and typography choices with Klaviyo Brand Voice: 7 Steps to Stay Consistent and Convert More.
Pair strong type hierarchy with clickable layouts using Klaviyo Product Block: 6 Easy Ways to Drive Clicks.
FAQs
1. What if I want custom fonts in sign-up forms too?
You can use custom fonts in forms. Add the font to Content → Images & brand → Fonts, then apply it in your form styles. See Custom fonts in sign-up forms and Klaviyo-hosted fonts.
2. Do Adobe Fonts require a subscription or special URL?
Yes. An active Adobe Fonts plan is required, and you paste the kit CSS URL that looks like
https://use.typekit.com/xxxxx.css.
3. Can I upload a font file to Klaviyo?
No. Host the font yourself or use Google Fonts or Adobe Fonts, then Import Font in Klaviyo.
4. Will Gmail show my custom font?
Gmail generally does not load web fonts. A notable exception is Roboto. Plan a close web-safe fallback.
5. Do buttons and product blocks respect custom fonts?
Yes. Set the font in the template Styles or each block’s Styles so CTAs and product blocks inherit it.
Conclusion
Custom fonts help your emails look like your brand. Some inboxes will not load them, so you need a good fallback. Add your fonts the right way in Klaviyo, apply them to templates and blocks, and test on real devices. Keep body text large and easy to read. Use only a few weights so emails load fast.
With these steps, your designs stay consistent and clear, and your readers can scan and act quickly. Make your typography a signature your customers recognise at a glance.
Key Takeaways
Three ways to add: Google, Adobe or hosted via Import Font, saved for reuse.
Plan fallbacks: Many inboxes show the fallback, especially Gmail and Yahoo.
Apply in styles: Set fonts in template styles and in each block, including buttons and product blocks.
Test widely: Use Inbox testing and Preview & test to check your top clients before you send.
Stay readable: Use at least 14 px body and about 1.5 line height for easy scanning on mobile.
Host correctly: For imported fonts, enable CORS on your host so fonts load reliably.
Tired of default fonts making your designs feel flat?
Make your message stand out in the inbox with visually distinct, mobile-optimised custom fonts that drive conversions. Click here to book your free Klaviyo audit to unlock design-led performance improvements.
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