Websites should serve fonts as WOFF2: it is the smallest font format and every current browser supports it. Font files from a foundry or a design team usually arrive as TTF or OTF, though, and sometimes all you have is the WOFF or WOFF2 file from a site's build folder when you need to install the typeface on your computer. This converter handles all four formats in both directions.
Each converted font comes with an optional preview image showing the typeface at several sizes, so you can see at a glance which file is which. The conversion runs on your device; licensed or unreleased fonts are never uploaded.
TTF, OTF, WOFF and WOFF2 explained
TTF (TrueType) and OTF (OpenType with PostScript-style CFF outlines) are the desktop formats you install in Windows, macOS or Linux. Both are built from the same structure, called sfnt: a set of tables holding the glyph outlines, character map, kerning, OpenType features and names. WOFF and WOFF2 are wrappers around exactly that structure, designed for the web. WOFF 1.0 compresses each table with zlib. WOFF2 uses Brotli compression plus transforms of the glyph data, and the resulting files are often around half the size of the original TTF, sometimes less.
Because the wrappers contain the same tables, converting between these formats does not redraw or simplify anything. Every glyph, kerning pair, ligature, OpenType feature and variable-font axis is carried over unchanged. The converter does not subset fonts, rename them or change their hinting.
When to convert a font
Self-hosting web fonts
Serving fonts from your own domain avoids depending on a third-party font service. Convert the TTF or OTF to WOFF2, reference it in an @font-face rule with format("woff2"), and the font loads quickly in every modern browser.
Installing a web font on your computer
Operating systems do not install WOFF or WOFF2 files. Choose TTF / OTF to get the original desktop font back, so you can use it in a design app or a word processor for mock-ups that match the website.
Supporting older environments
A few old browsers, email clients and embedded web views understand WOFF but not WOFF2. Converting to WOFF as well lets you list both in @font-face, with WOFF2 first.
How the converter works
The file's first bytes identify its real format, whatever its extension says. WOFF files are unwrapped and WOFF 1.0 output is written by the site's own code, using the browser's built-in zlib compression; a table that would not get smaller is stored as it is. WOFF2 uses wawoff2, Google's reference woff2 encoder and decoder compiled to WebAssembly. The compressor is about 1 MB and the decompressor a third of that; each is downloaded the first time you need it and runs in a Web Worker. The desktop choice, TTF / OTF, writes a .ttf for TrueType outlines and an .otf for CFF outlines, so you always get the right extension.
With Add a preview image switched on, the tool also produces a PNG next to each font, named like Brand-preview.png. It is 1200 pixels wide and shows the family name, your Preview text at four sizes, the alphabet in capitals and small letters, and the digits with common punctuation. The image is drawn with the converted file itself, so it also proves that a browser accepts the result. Leave Preview text empty to use the classic pangram The quick brown fox jumps over the lazy dog.
Comment utiliser cet outil
- Drop one or more .ttf, .otf, .woff or .woff2 files on the box above, or click Choose files (up to 30 MB each).
- Pick the Output format: WOFF2, WOFF or TTF / OTF.
- Keep Add a preview image on if you want a PNG specimen, and type your own Preview text if you like.
- Press Convert, then download each font and preview, or press Download all (.zip).
Limitations
- Font collections (.ttc files holding several fonts) are not supported.
- Older formats such as Type 1 (.pfb), EOT and SVG fonts are not accepted.
- The converter changes the container only. It does not subset a font to fewer characters, fix broken fonts or add missing glyphs.
- If the browser cannot load the font, no preview image is produced, although the converted font is still offered.
- Converting a font does not change its licence. Many desktop licences do not cover web embedding, so check the terms before you publish a font on a website.