Using Custom Fonts in Emails
Generate custom font images for emails using SVG, PNG, and Base64 formats without design software.
What is Using Custom Fonts in Emails?
custom-fonts-in-emails is a Node.js library that generates images with custom fonts for use in HTML emails. It allows developers to programmatically create SVG, PNG, or Base64-encoded graphics from text, replacing the need to manually design images in software like Photoshop. The library handles font detection, retina scaling, and fallback styling to ensure emails render correctly across clients.
Developers building email templates or transactional email systems who need to incorporate brand-specific typography without relying on design tools. It's particularly useful for Node.js-based email pipelines using nodemailer or Lad.js.
It dramatically simplifies embedding custom fonts in emails by automating image generation, supporting retina displays, and providing offline-compatible fallbacks—all through a clean, promise-based API.
Overview
An extremely easy way to use custom fonts in emails without having to use art software.
Use Cases
Best For
- Adding branded typography to marketing email templates
- Generating dynamic text images for transactional emails
- Creating retina-ready graphics for high-DPI email clients
- Automating email asset generation in CI/CD pipelines
- Embedding custom fonts in emails without design software
- Ensuring email accessibility with built-in fallback attributes
Not Ideal For
- Projects where email load time is critical and image bloat must be minimized
- Teams needing fully accessible, selectable text in emails without image fallbacks
- Environments with strict security policies that restrict dynamic image generation
- Applications that require real-time email rendering with sub-second latency
Pros & Cons
Pros
Uses os-fonts and fast-levenshtein to find fonts across system and npm, even with typos, reducing manual configuration.
Generates @2x and @3x PNGs using sharp, ensuring crisp display on high-DPI screens without extra work.
Adds alt text, title, and inline styles to images, maintaining readability when images fail to load.
Designed to work with nodemailer and Lad.js, fitting naturally into Node.js email pipelines.
Cons
Converts text to images, increasing email size, reducing accessibility, and preventing text selection or search.
On-the-fly image generation for each email can be CPU-intensive and may not scale well for high-volume sends.
Relies on sharp, which has native bindings that can cause installation issues in certain environments like Alpine Linux.
Open Source Alternative To
Using Custom Fonts in Emails is an open-source alternative to the following products:
Frequently Asked Questions
Related Projects
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