Fix ‘Substituted with Default Font’ in PDFs

This happens more often than you’d think. Whether your PDF was exported from Word, Docs, or another tool, font substitution can break layouts, cause size changes, and make shared files look unprofessional.

Let’s walk through what’s really happening — and how to fix it fast using the best PDF editor.

What Does “Substituted with Default Font” Mean?

This message means the font used in the original file isn’t available on the device you're using to view the PDF.

As a result, the PDF viewer replaces it with a default font — often Times New Roman, Helvetica, or Courier.

This issue leads to:

• Layout distortion
• Smaller or oversized font rendering
• Missing symbols or special characters
• Bold and italic formatting being stripped out

It usually affects files exported from:

• Microsoft Word without embedded fonts
• Google Docs, which don’t guarantee font preservation
• Design apps using licensed or custom fonts

The root cause? Fonts that weren’t embedded when the PDF was created.

How to Avoid Font Substitution in the First Place

The best way to avoid font substitution in PDFs is to embed fonts during export. This tells the PDF to carry the font data with it—so it’ll look the same on any device.

In Microsoft Word: 1. Go to File > Options > Save 2. Check “Embed fonts in the file” 3. Save your file as a PDF

This ensures the fonts travel with your document—even if the recipient doesn’t have them installed.

In Google Docs:

• Google Docs doesn’t allow font embedding.
• When you Download > PDF Document (.pdf), Docs uses a close match.
• But this often triggers font substitution in PDF viewers.

If that’s what happened, don’t worry—you can fix it easily with Smallpdf.

Step-by-Step: How to Fix Substituted Fonts in a PDF

Let’s say you already have a PDF showing the substituted with default font message. Here’s how to replace the broken text with the correct formatting.

1. Open the PDF in Smallpdf

• Go to Edit PDF
• Upload the document showing substitution issues

2. Use the Text Tool

• Click “Text” from the toolbar
• Click the spot where the wrong font appears
• Re-type the original content

3. Apply Bold or Italics if Needed

• Highlight the text
• Choose the correct weight from the font dropdown
• You can also press the bold “B” in the toolbar to apply bold weight directly.

4. Resize and Align

• Use the size control to match the original formatting
• Drag your new text layer over the old one
• Delete or hide the substituted version underneath

This gives you full control over the output — without needing to go back to Word or Docs.

Why Fonts Get Substituted (Even When You Think They’re Embedded)

Still not sure why this keeps happening? Here are a few common causes:

• Custom or third-party fonts aren’t licensed for embedding
• Fonts were applied using styling (like fake bold) instead of real weights
• You used a free font that only exports in regular, not bold or italic
• PDF creation tools stripped font data to reduce file size

If you’ve seen error messages like font substitution in Word or noticed that font substitution in PDF breaks your design—this is why.

What Fonts Can You Use Safely in Smallpdf?

We support the most reliable cross-platform fonts, including:

• Arial
• Courier
• Helvetica
• Times New Roman

Each font includes its Bold version too. These fonts will display correctly across devices, browsers, and print settings — making them perfect for editing documents where formatting must stay consistent.

Fix Font Substitution and Keep Your Layout Intact

Font issues don’t have to ruin your PDF. With Smallpdf, you can:

• Restore proper styling after PDF font substitution
• Use supported fonts that never trigger substituted with default font messages
• Reapply missing bold or italic text directly
• Share, send, or print a clean, consistent version — without surprises

Make Your Fonts Show Up Every Time

You don’t have to guess which font will stick. If you’ve run into problems like:

• Substitute font showing up in shared PDFs
• Font substitution in Word-to-PDF exports
• How to substitute fonts in a PDF the right way

Smallpdf gives you a direct fix. Use our Edit PDF tool to replace broken fonts, reapply styling, and keep your content looking exactly the way you designed it.

FAQs

How do I know if a font has been substituted in my PDF?

Most PDF viewers will display a warning like “font substituted with default” or “missing font.” You’ll also notice layout shifts, lighter text, or missing formatting.

Can I substitute a font manually in a PDF?

Yes — use Smallpdf’s Edit PDF tool to re-type and style text using supported fonts like Arial or Times New Roman. You can apply bold directly by pressing the bold “B” in the toolbar.