How to Adjust Font Substitution When Sharing Word Files

When you share a Word document with someone who does not have the fonts you used installed, Word automatically substitutes missing fonts with available ones. This substitution can change the document layout, line breaks, and overall appearance. The feature is called font substitution, and it can cause unexpected formatting shifts. This article explains how font substitution works, how to see which fonts are being substituted, and how to adjust the substitution settings so your shared document looks as intended.

How Font Substitution Works in Word

Font substitution occurs automatically when Word opens a document that contains fonts not installed on the current system. Word uses a built-in mapping table to replace each missing font with a similar font that is available. The goal is to preserve the document structure, but the substituted font may have different metrics such as character width, height, and spacing. This difference can cause text to reflow, tables to misalign, and page breaks to shift.

Word does not notify you about substitutions unless you check the font substitution dialog. The substitutions are applied only for the current session on that machine. When you save the document, the original font names are preserved in the file, so the next person who opens it will see the substitutions again if they also lack the fonts.

What Triggers Font Substitution

Font substitution is triggered when you or a collaborator opens a Word file on a device that lacks the specific font family used in the document. Common scenarios include:

• Sharing a document created with a premium or custom font that is not included with Windows or Microsoft 365
• Opening a document on a mobile device or Word for the web, which has a limited font set
• Using a document with fonts from an older version of Word that are no longer bundled with newer versions

Steps to View and Adjust Font Substitution

Follow these steps to see which fonts are being substituted and to change the replacement font if needed. You must have the document open in Word for Windows or Word for Mac.

1. Open the Font Substitution dialog
   Click File > Options > Advanced. Scroll down to the Show document content section. Click the Font Substitution button. A dialog appears listing every missing font and the font that Word is using as a substitute.
2. Review the list of substituted fonts
   The dialog shows two columns: Missing document font and Substituted font. Each row represents one font that is not installed on your system. The substituted font is the one Word chose automatically.
3. Change a specific substitution
   Select a font from the Missing document font list. In the Substituted font dropdown, pick a different installed font. Word immediately updates the preview in the document. Click OK to apply the change.
4. Convert all substitutions permanently
   If you want to remove the dependency on the missing fonts entirely, select a missing font, click Convert, and then click Yes. Word replaces every occurrence of that missing font with the substituted font and updates the font name in the document. After conversion, the font is no longer listed as missing.

Alternative Method: Embed Fonts to Prevent Substitution

Instead of adjusting substitutions after the fact, you can embed the original fonts inside the Word file. Embedding ensures the document looks the same on any system that supports embedded fonts.

1. Open Save options
   Click File > Options > Save.
2. Enable font embedding
   Check the box labeled Embed fonts in the file. To reduce file size, also check Do not embed common system fonts. Common fonts like Calibri and Arial are already present on most systems, so embedding them is unnecessary.
3. Save the document
   Click OK and then save the document. The file size increases by the size of the embedded fonts. Recipients who open the file will see the original fonts and no substitutions.

Common Issues When Adjusting Font Substitution

Font Substitution Button Is Grayed Out

The Font Substitution button in File > Options > Advanced > Show document content is only active when the current document contains at least one missing font. If all fonts in the document are installed on your system, the button remains disabled. Open a document that was created with fonts you do not have installed to access the dialog.

Substituted Font Changes the Layout

Even when you manually select a substitute font, the line breaks and page breaks may still be different from the original. This is because every font has unique character widths. To restore the exact layout, install the original font or embed fonts before sharing.

Embedded Fonts Increase File Size

Embedding fonts can increase the file size significantly, especially for fonts with many glyphs or multiple weights. A single font file can be 1 MB to 10 MB. If you share large documents frequently, consider using standard fonts such as Calibri, Arial, Times New Roman, or Aptos, which are preinstalled on most Windows and Microsoft 365 systems.

Font Embedding Not Available in Word for the Web

Word for the web does not support embedding fonts. If you edit a document that has embedded fonts in the browser, the embedded fonts are preserved but not used during editing. Substitution may occur temporarily. For consistent results, edit font-heavy documents in the desktop version of Word.

Item	Font Substitution	Font Embedding
How it works	Replaces missing fonts with available fonts on the recipient’s system	Stores the original font files inside the document
File size impact	No change to file size	Increases file size by the size of the font files
Layout preservation	May alter line breaks, page breaks, and spacing	Preserves exact layout as long as the recipient’s system supports embedded fonts
Recipient action needed	None	None
Compatibility	Works in all versions of Word and Word for the web	Works in Word desktop apps; limited in Word for the web

You can now view font substitutions in any shared Word document and change the replacement font to one that better preserves your layout. If you frequently share files with collaborators who may not have your fonts, enable font embedding in File > Options > Save before sending the document. For documents that must stay small, stick with common system fonts like Calibri or Aptos and avoid custom typefaces altogether.