Add your OTF file
Drop one or more .otf files onto the converter above, or browse for them. They load into browser memory only — nothing is uploaded, so there is no size-based pricing and no server queue.
OTF to WOFF
Converting a .otf font to .woff repackages the same glyphs and metrics for a different delivery target. Free, private, and validated — the file never leaves your browser.
Private for supported formats — processed in your browser
Runs on your deviceConvert supported files
Drop OTF files here
Batch files can each use a different output. Nothing uploads for local conversions.
Working inputs include camera RAW, browser-local audio/video, PDF, CBZ/CBR comics, office documents, ebooks, markup, 3D models, structured text, images, and archives.About converting OpenType font to WOFF web font
Converting a .otf font to .woff repackages the same glyphs and metrics for a different delivery target. An .otf file is an OpenType font, most often one whose glyphs are drawn with PostScript-style cubic Bezier outlines stored in a CFF table. OpenType's real contribution is its layout intelligence: ligatures, small caps, contextual alternates, and complex-script shaping all live in standardized tables inside the font.
WOFF, extension .woff, wraps an OpenType or TrueType font in zlib compression plus a small header and an optional metadata block, creating a format websites could legally and efficiently serve. It was the format that ended the web's font drought and made @font-face mainstream. For this route the practical draw is broad legacy reach, with browser support stretching back to IE9 and Android 4.4 and lossless wrapper with licensing-friendly metadata — balanced against superseded by WOFF2's stronger compression, which is worth knowing before you commit a large batch.
Why convert OTF to WOFF?
The practical trigger for this conversion is usually a mismatch: with .otf, cFF rendering at small sizes on low-DPI screens historically trailed well-hinted TrueType. Switching to .woff buys you broad legacy reach, with browser support stretching back to IE9 and Android 4.4, which is why it is the better fit for web-font serving for audiences on older browsers such as IE9 and early Android. Because the conversion runs locally, trying it costs nothing but a few seconds of compute on your own machine.
OTF vs WOFF at a glance
| Aspect | OpenType font (.otf) | WOFF web font (.woff) |
|---|---|---|
| Format type | Container — quality depends on the codecs and settings inside | Container — quality depends on the codecs and settings inside |
| How it stores data | uses the same sfnt table architecture as TrueType; the .otf extension conventionally signals CFF (cubic) outlines, while .ttf signals quadratic glyf outlines | each sfnt table is individually zlib-compressed, so the structure mirrors the original font table for table |
| Strongest at | professional typesetting where advanced typographic features matter | web-font serving for audiences on older browsers such as IE9 and early Android |
| Weak spot | cFF rendering at small sizes on low-DPI screens historically trailed well-hinted TrueType | superseded by WOFF2's stronger compression |
| Metadata | name-table records cover naming, version, designer, description, and full license text, and the OS/2 fsType bits encode the embedding permissions that font licensing hinges on | beyond the wrapped font's own name table, the extended metadata block stores vendor, credits, description, and license information as XML |
Pick WOFF as the output
Select .woff in the output menu next to each file. The menu only offers targets this engine can genuinely produce, so if WOFF is selectable, the route is real and validated.
Convert on your device
Press Convert. The font tables are parsed and rewritten locally with fonteditor-core; glyph outlines, hinting, and kerning survive the trip.
Verify and download
Each result is signature-checked before the download unlocks, so a failed encode can never masquerade as a valid WOFF file. Outputs keep the original filename with the .woff extension.
OTF to WOFF questions, answered
Will converting OTF to WOFF lose quality?
Since otf is container-oriented and woff is container-oriented, the conversion preserves the source content exactly as stored; no additional compression pass is applied beyond what .woff itself requires.
Is it private to convert OTF files here?
Yes — the .otf file is processed inside your browser tab and never uploaded. The font tables are parsed and rewritten locally with fonteditor-core; glyph outlines, hinting, and kerning survive the trip. Close the tab and the file is gone from memory.
Where will the WOFF file work?
Support reaches much further back than WOFF2 — IE9, early Chrome and Firefox, and old mobile browsers all handle .woff — which kept it in font stacks for years as a safety net. Modern sites increasingly ship WOFF2 alone, and operating systems continue to require unwrapping before a .woff can be installed.
Will the WOFF file be bigger or smaller than my OTF?
It depends on the content: each sfnt table is individually zlib-compressed, so the structure mirrors the original font table for table. Convert one representative file first and compare before batch-processing a large set.
What happens to the metadata in my OTF file?
In .otf, name-table records cover naming, version, designer, description, and full license text, and the OS/2 fsType bits encode the embedding permissions that font licensing hinges on. Re-encoding through the browser pipeline does not carry embedded metadata into the output, which doubles as a privacy scrub — check the exported file if you specifically need tags preserved.