What is a WOFF file?
WOFF stands for Web Open Font Format. It was created by the World Wide Web Consortium and first released in 2009. WOFF is a TrueType or OpenType font with each table compressed and a small header added, which makes web fonts smaller to download. The font inside is unchanged.
| Type | font |
|---|---|
| Compression | Lossless |
| In a browser | loads in every browser through CSS; cannot be installed on a computer |
| Common uses | fonts served by websites |
| MIME type | font/woff |
Which format should you convert WOFF to?
- WOFF to TTF to install the font on a computer.
- WOFF to OTF to install the font and use it in design software.
How to open a WOFF file
Whether a WOFF file opens with a double click depends on the device. Here is what works on each, without buying software:
| Windows | Double-click a TTF or OTF to preview and install it. WOFF files are for websites and do not install. |
|---|---|
| Mac | Double-click a TTF or OTF to open Font Book and install it. |
| iPhone and iPad | Fonts install through apps or configuration profiles; the Files app can preview some. |
| Android | Most phones cannot install system fonts; apps with custom font options can use the file. |
| Web browser | WOFF loads in every browser through CSS; cannot be installed on a computer. |
Want the technical details? See what a .woff file is, with its MIME type, file signature and a viewer.
WOFF compared with other font formats
How WOFF stacks up against the formats people most often convert it to or from:
| Format | Compression | Usually contains | Released | Best for |
|---|---|---|---|---|
| WOFF | Lossless | the tables of a TrueType or OpenType font, each compressed | 2009 | fonts served by websites |
| TTF | Lossless | glyph outlines drawn with quadratic curves | 1991 | installing fonts on a computer and embedding them in documents |
| OTF | Lossless | glyph outlines, usually cubic PostScript curves, plus typographic features | 1996 | professional typography, ligatures and design work |
How to use the WOFF converter
- Choose the format you want in the Convert to menu.
- Drop your WOFF files on the box, or press Choose WOFF files. Several files can go in at once.
- Adjust the settings if you need to; the defaults suit most people.
- Press Convert and save each file with its Download button. Converting to SVG, WOFF2 uses our server, which deletes the file right after; the rest never leave your device.
Tips for converting WOFF files without losing anything
Converting a WOFF file is lossless: every glyph, kerning pair and feature is copied exactly, and only the packaging changes.
- Check the licence before converting a font for the web: many desktop licences do not allow web embedding.
- Serve WOFF (or WOFF2) to browsers and keep TTF or OTF for installing on computers.
- Converting between TTF, OTF, WOFF and WOFF2 keeps the design of every glyph; only a change between TrueType and PostScript outlines redraws the curves, with no visible difference.
- Subsetting a font to the characters you use is the biggest saving for web pages.
- Test the converted font in a browser page before rolling it out, to confirm every weight and style is linked in your CSS.
- Keep one family per folder with clear file names such as Brand-Bold.woff, so the right weight is always loaded.
- Variable fonts convert the same way; the axes and named instances travel with the font tables unchanged.
Convert WOFF files from the command line
The fontTools library for Python converts between font and web font formats:
python3 -c "from fontTools.ttLib import TTFont; f = TTFont('input.woff'); f.flavor = None; f.save('output.otf')"The converter on this page does the same job in your browser, without installing anything.
WOFF converter FAQ
What is a WOFF file?
WOFF stands for Web Open Font Format, a font format created by the World Wide Web Consortium in 2009. WOFF is a TrueType or OpenType font with each table compressed and a small header added, which makes web fonts smaller to download. The font inside is unchanged.
How do I open a WOFF file?
WOFF loads in every browser through CSS; cannot be installed on a computer. If the program you need will not open it, convert it to a more widely supported format above.
What is the most common WOFF conversion?
WOFF to OTF is the conversion people search for most. The WOFF's tables are decompressed and reassembled into a standard font file, exactly as it was before it was packed for the web.
Does converting WOFF files here upload them?
Only for some conversions. Converting to SVG, WOFF2 uses our conversion server, where the file is deleted as soon as the result is sent back; the other conversions run inside your browser and never leave your device.
Is the WOFF converter free?
Yes. There is no sign-up and no watermark. Conversions that use our server accept files up to 25 MB, with a fair-use limit per hour. The site is supported by advertising.
Can I convert WOFF files on iPhone or Android?
Yes. Open this page in Safari on iPhone and iPad, or in Chrome on Android, choose your WOFF files and download the results to your Downloads folder.
Can I convert several WOFF files at once?
Yes. Drop as many as you like; they are converted one after another, each with its own download button.