# TTF to WOFF Converter

> Convert TrueType (.ttf) fonts to Web Open Font Format (.woff).

TTF to WOFF Converter converts font files between TTF, OTF, WOFF, WOFF2, and Base64 CSS definitions locally in your web browser. Font data processing runs entirely on your device without transmitting files over the network.

**URL:** https://convertto.tech/t/ttf-to-woff
**Category:** Developer Tools (https://convertto.tech/c/developer-tools)
**Privacy:** Runs entirely in the browser; no upload
**Cost:** Free, no sign-up
**Last updated:** 2026-08-01

## Key facts

- **Privacy:** Runs entirely in your browser — nothing is uploaded
- **Cost:** Free, unlimited, no sign-up

## What WOFF adds to a TTF

WOFF 1.0 wraps an existing sfnt font for web delivery. The W3C Recommendation defines a 44-byte header, a table directory, the font tables, then an optional extended metadata block and an optional private data block. Each table may be compressed individually with the zlib `compress2()` function. The font itself is untouched: the spec requires the same set of tables as the input font, and requires that a decoder restore them so the font displays identically.

Two things the wrapper buys that raw `.ttf` hosting does not. The container is font-specific, so a browser can reject a malformed file before handing it to the rasteriser, and the metadata block gives a foundry somewhere to state licensing and credits that travels with the file rather than sitting in a text file nobody reads.

## WOFF or WOFF2?

WOFF2, for anything you actually serve. It compresses the whole font with Brotli instead of compressing each table with zlib, and it preprocesses `glyf`, `loca` and `hmtx` first so the compressor has less to work with. WOFF 1.0 is worth generating only as a fallback source for browsers that predate WOFF2 support, and on most sites that audience is now too small to justify the second file. Generate the primary with [TTF to WOFF2](https://convertto.tech/t/ttf-to-woff2) and add this one only if your analytics say you need it.

```css
@font-face {
  font-family: 'Example Sans';
  src: url('/fonts/example-sans.woff2') format('woff2'),
       url('/fonts/example-sans.woff') format('woff');
  font-display: swap;
}
```

The browser takes the first entry whose `format()` it recognises, so WOFF2 is listed first and the WOFF line is only ever reached by an engine that cannot read the line above it.

## Round-tripping

Because WOFF preserves table data rather than re-rendering outlines, unwrapping gives the font back unaltered, and [WOFF to TTF](https://convertto.tech/t/woff-to-ttf) does exactly that. The file will not always be byte-identical to the original: the spec makes the table directory rebuild in ascending tag order, and any unreferenced padding in the source is dropped when the WOFF is made. For a well-formed input font, with correct padding, correct checksums and no extraneous data between tables, the round trip preserves everything that affects rendering.

| Format | Outline data | Compression | Where it belongs |
| --- | --- | --- | --- |
| `.ttf` TrueType | Quadratic curves in the `glyf` and `loca` tables | None | Desktop installation, Android build pipelines, tools that only read `glyf` |
| `.otf` OpenType with PostScript outlines | Cubic curves in a `CFF ` or `CFF2` table | None | Desktop installation, print and design applications |
| `.woff` WOFF 1.0 | Whichever of the two the wrapped font already used | zlib, applied to each table separately | A fallback source for browsers too old for WOFF2 |
| `.woff2` WOFF 2.0 | Whichever of the two the wrapped font already used | Brotli over the whole font, after a reversible transform of `glyf`, `loca` and `hmtx` | The format to actually serve on the web |
| `.eot` Embedded OpenType | Either, wrapped in a Microsoft-specific container | Optional MicroType Express | Internet Explorer 8 and earlier. A W3C Member Submission that never became a standard |
| `.ttc` / `.otc` collection | Either, with tables shared between several faces | None on its own, though WOFF2 can wrap a collection | Shipping a whole family in one file, common for CJK fonts |

*TTF and OTF are two flavours of the same sfnt container. WOFF and WOFF2 are packaging placed around one of them, not a third kind of outline.*

> **Check the licence before you convert** — Converting a font modifies it, and plenty of commercial licences forbid exactly that. A licence that allows you to install a font on your own machine very often does not allow you to embed it in a web page, redistribute it, or hand a converted copy to anyone else. The OpenType `OS/2` table carries an `fsType` field in which the foundry declares its embedding permission, with values covering installable, restricted licence, preview and print, and editable embedding, and a converter that rebuilds the font can drop or flatten that declaration. Read the EULA first, and use the foundry web kit when one is offered.

## Related font conversions

- [TTF to WOFF2](https://convertto.tech/t/ttf-to-woff2) for the file that should be first in your `src` list.
- [WOFF to TTF](https://convertto.tech/t/woff-to-ttf) to unwrap a web font again.
- [OTF to TTF](https://convertto.tech/t/otf-to-ttf) when the source family has PostScript outlines.
- [Font to Base64](https://convertto.tech/t/font-to-base64) to inline a small face into CSS instead.
- Format hubs: [WOFF](https://convertto.tech/f/woff), [WOFF2](https://convertto.tech/f/woff2), [TTF](https://convertto.tech/f/ttf) and [OTF](https://convertto.tech/f/otf).

## How to use

1. Select your font file — the file stays on your device and is never uploaded.
2. Press Run, then download the result when it is ready.

## FAQ

### Is my font file uploaded anywhere?

No, font conversion happens entirely in your browser using JavaScript.

### What is the difference between OTF and TTF?

Both are OpenType fonts using the same sfnt container. A TTF stores glyph outlines as quadratic curves in the glyf and loca tables; an OTF stores them as cubic curves in a CFF or CFF2 table. The extension reflects which outline format the file uses, and the rasteriser decides by reading the version tag inside the file rather than the extension.

### Is converting a font lossless?

Unwrapping WOFF or WOFF2 back to sfnt is defined to be reversible, so the table data comes back intact. Converting between outline formats, such as OTF to TTF, is not: cubic curves have to be approximated by quadratics, and hinting and variable-font axes do not carry over.

### Am I allowed to convert a commercial font?

Often not. Many font licences forbid modification, web embedding or redistribution, and converting a font is a modification. The OS/2 table carries an fsType field in which the foundry declares its embedding permission. Check the EULA before converting a font you did not make.

### Can I convert an EOT or TTC file here?

No. This tool accepts TTF, OTF, WOFF and WOFF2. EOT is a retired Microsoft container for Internet Explorer 8 and earlier, and TTC is a collection holding several faces in one file, which needs a different unpacking step.

## Sources

- [OpenType specification](https://learn.microsoft.com/en-us/typography/opentype/spec/) — Microsoft
- [OpenType font file structure (sfnt)](https://learn.microsoft.com/en-us/typography/opentype/spec/otff) — Microsoft
- [WOFF File Format 1.0](https://www.w3.org/TR/WOFF/) — W3C
- [WOFF File Format 2.0](https://www.w3.org/TR/WOFF2/) — W3C
- [OpenType OS/2 table (fsType embedding permissions)](https://learn.microsoft.com/en-us/typography/opentype/spec/os2) — Microsoft
- [RFC 1950: ZLIB Compressed Data Format Specification](https://www.rfc-editor.org/rfc/rfc1950) — IETF
- [CSS Fonts Module Level 4](https://www.w3.org/TR/css-fonts-4/) — W3C

## Related tools

- [Font to Base64 & CSS Generator](https://convertto.tech/t/font-to-base64): Convert font files directly into CSS @font-face data URIs.
- [OTF to TTF Converter](https://convertto.tech/t/otf-to-ttf): Convert OpenType (.otf) fonts to TrueType (.ttf) format.
- [TTF to WOFF2 Converter](https://convertto.tech/t/ttf-to-woff2): Convert TrueType (.ttf) fonts to optimized WOFF2 web fonts.
- [WOFF to TTF Converter](https://convertto.tech/t/woff-to-ttf): Convert WOFF web fonts back to desktop TrueType (.ttf) fonts.
- [WOFF2 to TTF Converter](https://convertto.tech/t/woff2-to-ttf): Decompress WOFF2 fonts back to TTF format.
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