WOFFer – WOFF font converter

WOFF font file icon

This handy tool converts TTF and OTF fonts to WOFF format and back to TTF or OTF.


Note: This app uses cutting-edge web technologies. If it behaves strangely, please try using a recent version of Chrome or Firefox.

Important: Only convert fonts whose licenses allow you to do so.

How To Use

To convert your fonts:

  1. Select a WOFF, TTF, or OTF file to convert.

    You can either drag and drop the font into the box, or click the Choose Files button.

  2. Wait for the font(s) to convert.

    Be patient, especially when converting TTF or OTF to WOFF, as this is a computationally-intensive task.

  3. Download the converted fonts

    You can download the fonts individually, or in a single zip file.


The WOFFer is a tool to convert TTF or OTF to WOFF and back to TTF or OTF. WOFF, short for Web Open Font Format, is a compressed font format optimized for use on the web. This format compresses the font data using zlib, which can greatly reduce the size of the font for faster loading.

This tool is powered by WOFFjs, a JavaScript implementation of an encoder and decoder for WOFF fonts. This tool does not transmit your fonts to a server; instead, they are processed entirely inside your browser. You don’t need to worry about crashing my server or possibly violating the terms of your font license, as all of the work is done locally.

Conversion to the WOFF format with this tool may be slow, because it uses Google’s Zopfli algorithm to compress the font data, yielding smaller files but a much longer conversion time.

If this tool helped you or saved you some time, you can donate to encourage further development and maintenance of programs like this.

Known Issues

  • Large fonts will crash the conversion process. If a font is “processing” for too long and the font is more than a couple megabytes, you have probably run into this issue. I am working on a way to handle large fonts.
  • Safari may fail to download converted fonts.