# Font resolution events

> Detect missing fonts at load time and handle them before your users notice.

2026-01-28 · Caio Pizzol

Documents move between systems. Fonts don't always follow. Now you can detect and handle unsupported fonts before your users notice.

## The problem

A contract created in Word with Calibri looks right on the author's machine. Open it in a web-based editor without that font installed, and the layout shifts — line breaks change, tables overflow, headers wrap differently. Your users see a broken document and blame your app, not the missing font.

Until now, there was no reliable way to detect this at load time and respond before the damage was visible.

## The FontsResolved event

SuperDoc now emits a `fonts-resolved` event after loading a document. It tells you exactly which fonts loaded successfully and which ones are missing from the user's environment.

```typescript
superdoc.on('fonts-resolved', ({ documentFonts, unsupportedFonts }) => {
  if (unsupportedFonts.length > 0) {
    showNotification(
      `Unsupported fonts: ${unsupportedFonts.join(', ')}. Layout may differ from the original.`
    );
  }
});
```

## What you can build with it

The event gives you the data. What you do with it is up to your product:

- **Show a user-facing alert** when fonts are missing, so users understand why the document looks different
- **Dynamically update toolbar font options** to only show fonts that are actually available
- **Log font issues** to track which fonts your users' documents rely on most
- **Load fonts on demand** from a CDN or your own font server when a missing font is detected

```typescript
superdoc.on('fonts-resolved', async ({ unsupportedFonts }) => {
  for (const font of unsupportedFonts) {
    const hosted = await fetchFontFromCDN(font);
    if (hosted) {
      document.fonts.add(hosted);
    }
  }
});
```

## Consistent rendering across the pipeline

Font handling is now more predictable across the full lifecycle: editing, rendering, and export. Mixed-style runs from imported `.docx` files — where a single paragraph uses multiple fonts — resolve consistently instead of falling back unpredictably.

The result: what your users see in the editor matches what they get when they export or print.

## Get started

Listen for the `fonts-resolved` event on any SuperDoc instance. No configuration needed — the event fires automatically on every document load.

[Read the docs]([https://docs.superdoc.dev/core/superdoc/events#fonts-resolved](https://docs.superdoc.dev/core/superdoc/events#fonts-resolved))