Convert TTF to OTF Online

How to Convert TTF to OTF Online

1. Upload Your TTF File: Drag and drop or click "+ Add Files" to load one or more .ttf files. Batch conversion is supported — drop an entire family (Regular, Bold, Italic, Bold Italic, plus weight variants) in a single pass. Files stay in your browser session; nothing is uploaded to a server.
2. Confirm OTF as the Output: The output is locked to OTF on this page — no codec or quality slider is needed. The conversion is a container rewrap: the underlying SFNT tables (glyf, cmap, GSUB, GPOS, kern, name, etc.) are preserved byte-for-byte, and the extension changes from .ttf to .otf. Existing OpenType layout features, kerning pairs, hinting bytecode, and variable-font axes carry over unchanged.
3. Review the File List (Optional): Reorder files, remove ones you don't want, or add more TTFs to the batch. If you only need a Latin subset for a specific project, subset the TTF first (pyftsubset from fonttools is the standard CLI) before converting — that strips unused glyphs and keeps the .otf smaller.
4. Convert and Download: Click "Convert." Each .otf downloads individually, or grab the whole batch as a ZIP. No sign-up, no watermark, no email required. Parsing happens locally via a lazy-loaded opentype.js worker.

Why Convert TTF to OTF?

TTF (TrueType Font) and OTF (OpenType Font) are both SFNT-based font containers — at the binary level, they share the same table-directory structure. TTF was developed by Apple in the late 1980s and licensed to Microsoft; OpenType was a 1996 joint Microsoft/Adobe extension that added support for Adobe's PostScript (CFF) outlines and richer OpenType layout features. In practice the .otf extension is associated with PostScript-flavored OpenType, but the spec explicitly allows a .otf file to contain TrueType (glyf) outlines — and that is exactly what most TTF-to-OTF conversions produce.

• Application compatibility for design suites — Adobe InDesign, Illustrator, Photoshop, Affinity Publisher, and QuarkXPress all accept both .ttf and .otf, but some templates, brand guidelines, and corporate font-management systems (Universal Type Server, FontExplorer X, Suitcase Fusion) are configured to expect .otf exclusively for OpenType-typed assets. Converting avoids "wrong format" rejections in those pipelines.
• Brand-asset normalization — Foundries often ship one weight as .ttf and another as .otf; a single family with mixed extensions is awkward to manage. Converting every weight to .otf (or .ttf — see OTF to TTF for the reverse) gives one tidy extension across the whole family directory.
• Lossless container rewrap — Converting TTF to OTF without re-encoding outlines is lossless. Every glyph, every kerning pair, every OpenType feature (liga, dlig, ss01, cv01, smcp, c2sc, kern, frac, tnum, onum), and every variable-font axis (wght, wdth, opsz, slnt, ital) carries over unchanged because the underlying SFNT tables are copied verbatim.
• Operating-system installation — macOS Font Book, Windows Font Settings, and Linux fontconfig all install .otf files the same way they install .ttf (double-click or drop into ~/Library/Fonts, C:\Windows\Fonts, or ~/.fonts). There is no rendering difference at install time; the OS reads the outline format from the SFNT directory, not the extension.
• Workflow tooling expects OTF — Some font-pairing plugins, Figma's font-import dialog, and a handful of older licensing/EULA enforcement tools key on the .otf extension when classifying assets. Standardizing on .otf smooths integration with those tools without altering the font itself.
• Preparing for further conversion — If your eventual target is web delivery, converting TTF → OTF first is unnecessary — go straight to WOFF2 or WOFF. But if your downstream consumer is an iOS app bundle, an embedded device font ROM, or a Type-1-only legacy system, an .otf container is the expected hand-off format.

TTF vs OTF — Format Comparison

Container Rewrap vs CFF Re-encoding — What This Tool Does

There are two ways a TTF-to-OTF converter can produce its output, and the distinction matters when you're comparing tools.

If you specifically need a CFF-flavored OpenType file (e.g., for a print workflow that requires PostScript outlines), use FontForge or Adobe's AFDKO makeotf after converting. The rewrap approach is the right default because it's lossless, fast, and preserves the original designer's hinting work.

Frequently Asked Questions

Is converting TTF to OTF lossless?

Yes — when the conversion is a container rewrap, every byte of every SFNT table (glyf, cmap, head, hhea, hmtx, name, post, OS/2, GSUB, GPOS, GDEF, kern, fvar, gvar, etc.) is preserved exactly. The only thing that changes is the file extension and, depending on the tool, the sfntVersion field in the table directory header. xconvert's converter uses opentype.js, which round-trips the table data; you should not see any rendering, kerning, or feature-behavior changes between the source .ttf and the resulting .otf.

Will my OTF have PostScript (CFF) outlines after conversion?

No. This converter does not re-encode TrueType (glyf) outlines into PostScript CFF. The output .otf contains the same quadratic Bezier glyf table the input had — it's TrueType-flavored OpenType, which the OpenType spec explicitly allows. If you need true CFF outlines, run the font through FontForge ("Generate Fonts… → OpenType (CFF)") or Adobe's AFDKO makeotf tool, both of which mathematically convert quadratic to cubic curves and emit a new CFF table.

Will the file size change?

For a container rewrap (this tool), the file size is essentially identical — within a few bytes, accounting for any minor table padding differences. Tools that re-encode to CFF can produce 10–20% smaller files for glyph-heavy fonts because CFF supports subroutinization (shared path segments), but you trade that for the loss of TrueType hinting bytecode. For most modern displays (HiDPI/Retina, where hinting matters less), the size savings can be worth it; for small-size on-screen rendering on older Windows displays, the original TrueType hinting is usually better.

Do ligatures, kerning, and stylistic alternates carry over?

Yes — all OpenType layout tables (GSUB, GPOS, GDEF, BASE, JSTF, MATH) are copied unchanged. If your TTF supports discretionary ligatures (dlig), stylistic sets (ss01–ss20), small caps (smcp/c2sc), old-style figures (onum), tabular figures (tnum), fractions (frac), or contextual alternates (calt), every one of those features works in the resulting OTF via CSS font-feature-settings or InDesign's OpenType panel. Important caveat: if a feature wasn't present in the source TTF, conversion cannot add it — features come from the foundry's font data, not the container format.

Will variable font axes survive the conversion?

Yes. The variation tables (fvar, gvar, STAT, HVAR, MVAR, VVAR) are copied byte-for-byte. A TrueType variable font with wght 100–900 and slnt -10–0 axes converts to an OTF with the identical axis definitions, named instances, and default values. CSS font-variation-settings: "wght" 650, "slnt" -7 continues to work as expected.

Why do some tools say my converted OTF "isn't really PostScript"?

Because it isn't. Font validators like fontbakery and font-info tools like otfinfo distinguish between TrueType-flavored OpenType (contains glyf) and PostScript-flavored OpenType (contains CFF or CFF2). After a container rewrap your .otf is technically TrueType-flavored OpenType — the sfntVersion may even still report 0x00010000 (TrueType) rather than OTTO (CFF). This is valid per the OpenType specification; foundries like Google Fonts ship many of their .otf releases as TrueType-flavored. If a downstream tool specifically requires a CFF table, you'll need a re-encoding converter (FontForge or AFDKO makeotf).

Is my font ever uploaded to a server?

No. The conversion runs entirely in your browser via a lazy-loaded JavaScript worker (opentype.js). Your .ttf file never leaves the browser session, which matters for unreleased fonts under NDA, commercial fonts with restrictive EULAs, and corporate brand assets. There is no upload, no server log, and no account required.

Can I do the reverse, OTF to TTF?

Yes — use the OTF to TTF converter. The reverse direction is more involved when the source OTF has CFF (PostScript) outlines, because cubic Beziers must be approximated as quadratic Beziers for the glyf table. xconvert handles that conversion automatically. If your source OTF is already TrueType-flavored (contains glyf), the reverse is also a clean container rewrap.

What's the difference between format("opentype") and format("truetype") in @font-face?

In modern browsers (Chrome 4+, Firefox 3.5+, Safari 3.1+, Edge 12+), both tokens are accepted hints to the browser about how to parse the file. The browser ultimately inspects the file's binary structure (the sfntVersion and table presence) to determine the outline format, so a mislabeled token will still work in current browsers. For maximum forward compatibility, match the token to the file: use format("truetype") for .ttf, format("opentype") for .otf. Better still, switch web delivery to WOFF2 and use format("woff2") — that's the standard for @font-face in 2026.