TTF ↔ OTF Converter
TTF and OTF are both SFNT containers — the difference is the outline format inside (TrueType quadratics vs CFF cubics). This tool detects the format and lets you rename safely.
Runs entirely in your browser — no upload, no registration.
What this tool does
Reads the sfntVersion header and tells you whether renaming the extension is a safe operation or whether a genuine reformat is required.
Why you might need it
Some legacy tools reject a file based on extension alone even though the bytes are valid. This tool fixes that without recompiling the font.
How to use it
- Drop a .ttf or .otf file.
- Read the compatibility note.
- Download the renamed file.
Limitations
- A true outline-format conversion (TrueType ↔ CFF) requires desktop tools like FontForge and cannot be done in the browser.
- Renaming does not change the actual glyphs.
Always review the included licence before commercial use. Do not remove copyright records, designer names, licensing metadata or embedding restrictions from any font you process.