WOFF2 vs TTF vs OTF: Which Font Format Does Your Website Actually Need

You bought a font, or downloaded a free one, and it arrived as a .ttf file. You want to use it on your website. So you upload the .ttf straight into your CSS and move on.

This works, technically. It also means your site is serving a font file that's often two or three times larger than it needs to be. Font formats are one of those small details that quietly affect page speed, and most people never think about them because the browser doesn't complain, it just loads slower than it should.

Here's what each format actually is and which one belongs where.

TTF and OTF: Made for Design Tools, Not the Web

TrueType (TTF) and OpenType (OTF) are the formats fonts are usually distributed in. A type foundry sells you a TTF or OTF file, or you download one from a free font site, and that's the format your design software expects.

The difference between the two is mostly internal. TTF stores letter shapes as quadratic curves. OTF can use the same system or a different one called PostScript outlines, which tends to produce cleaner curves for complex typefaces. For most practical purposes you won't see a visual difference between the two at normal reading sizes.

Neither format was designed with the web in mind. They carry data that's useful for an operating system or a design app, like hinting instructions and full glyph metadata, but a lot of that goes unused once the font is just being rendered in a browser tab. The result is a file that's bigger than it needs to be for web delivery.

WOFF and WOFF2: Built Specifically for Browsers

WOFF (Web Open Font Format) exists for one reason: compress the same font data into a smaller package that browsers can download faster. It wraps the same underlying font but applies compression on top, similar in spirit to how a ZIP file shrinks a document without changing its contents.

WOFF2 is the newer version and the one you should actually use. It switched to Brotli compression, which does meaningfully better than WOFF's older zlib compression. In practice, WOFF2 files run about 30 percent smaller than WOFF and up to 40 percent smaller than the original TTF, with zero change to how the letters look.

Every browser in current use supports WOFF2. There's no compatibility reason left to avoid it. If you're loading custom fonts on a website in 2026, WOFF2 should be the default, not an afterthought.

So Why Do TTF and OTF Still Matter?

Two situations still call for them.

If you're editing a font, adding glyphs, adjusting kerning, fixing a typo in a custom icon font, you need TTF or OTF because that's what font editors like FontForge or Glyphs expect. WOFF2 is a delivery format, not an editing format.

If you're installing a font on your own computer to use in design software, TTF or OTF is what your operating system wants. WOFF2 won't show up as an installable font in most font managers.

So the rule of thumb is simple: TTF and OTF for editing and installing, WOFF2 for shipping on a website.

What About OTF Converting Out as TTF?

If you've converted an OTF file and the result looks like TTF rather than another OTF, that's expected. OpenType fonts actually carry one of two different outline systems internally, either TrueType curves or PostScript curves. When a converter processes the file, it normalizes to TrueType outlines, so the practical output formats become TTF, WOFF, and WOFF2. The letterforms stay identical. Only the internal format changes.

Converting Between Them

If you've got a TTF or OTF file and need it for the web, or a WOFF2 file you need to open in a font editor, you don't need desktop software for this anymore. Our font converter handles TTF, OTF, WOFF, and WOFF2 conversion entirely in the browser using WebAssembly. Nothing gets uploaded, the glyph shapes stay exactly the same, and you get back whichever format you actually need.

The short version: if it's going on a website, convert it to WOFF2 first. Your pages will load faster and nobody will notice anything different about how the text looks, which is exactly the point.