WOFF to CID Converter

Transform web fonts into CID-keyed format for CJK support

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CJK Ready

Convert WOFF web fonts to CID-keyed format — unlock support for large character sets needed in Chinese, Japanese, and Korean publishing.

Private Conversion

Uploaded WOFF files are erased right after processing, and CID output is removed within 24 hours to keep your font data confidential.

Web-Based Workflow

No desktop font tools needed. Run the full WOFF to CID conversion through your browser on any device with an internet connection.

How to convert WOFF to CID

1

Select files from Computer, Google Drive, Dropbox, URL or by dragging it on the page.

2

Choose cid or any other format you need as a result (more than 200 formats supported)

3

Let the file convert and you can download your cid file right afterwards

About formats

WOFF (Web Open Font Format) is a web font container format developed by Jonathan Kew, Tal Leming, and Erik van Blokland, and standardized by the W3C as a Recommendation in December 2012. The format wraps existing TrueType or OpenType font data in a compressed container with additional metadata, specifically designed for efficient delivery over HTTP as part of web pages using the CSS @font-face rule. WOFF applies table-level zlib compression to the font data, typically achieving 40-50% size reduction compared to raw TTF or OTF files, while preserving every table and glyph exactly. An extended metadata block allows foundries to embed licensing information, credits, and descriptions that travel with the font file. WOFF was created to address a practical impasse: type foundries were reluctant to allow their fonts on the web in raw TTF/OTF form (easily installable as desktop fonts), while the web standards community needed a freely implementable font delivery mechanism. One advantage is universal browser support — every modern browser across desktop and mobile platforms renders WOFF natively, making it the baseline format for web typography. The distinct file signature and container structure also provides a licensing benefit, giving foundries a format distinguishable from desktop fonts while remaining technically straightforward. WOFF 2.0, standardized in March 2018, replaces zlib with Brotli compression for an additional 20-30% size reduction and has achieved similarly broad browser adoption. Together, WOFF and WOFF2 enabled the custom web typography revolution that transformed web design from a handful of system fonts to millions of typeface options.
Developer: W3C
Initial release: December 13, 2012
CID (Character Identifier) is a font architecture developed by Adobe Systems and specified in June 1993 to address the challenges of fonts containing very large glyph sets, particularly for CJK (Chinese, Japanese, Korean) scripts. Traditional PostScript fonts identify glyphs by name, which becomes impractical when a font contains tens of thousands of characters — a typical Japanese font may include over 20,000 glyphs. CID-keyed fonts replace glyph names with numeric identifiers organized by a character collection and ordering (such as Adobe-Japan1 or Adobe-GB1), dramatically reducing overhead for glyph access and subsetting. The architecture defines three PostScript font types: Type 9 (CID-keyed Type 1 outlines), Type 10 (CID-keyed Type 3), and Type 11 (CID-keyed Type 42/TrueType). A primary advantage is efficient handling of massive character sets — the numeric CID approach eliminates the memory and processing cost of maintaining thousands of glyph name strings. CID fonts also support sophisticated CMap resources that map encoding values to CIDs, enabling a single font to serve multiple encoding schemes (Unicode, Shift-JIS, Big5) without duplicating glyph data. The architecture integrates well with PDF subsetting, allowing documents to embed only the glyphs actually used. CID-keyed technology laid the foundation for CJK support in both OpenType and modern PDF workflows, and remains active in print production and document processing systems worldwide.
Developer: Adobe Systems
Initial release: June 11, 1993

Frequently Asked Questions

Why convert WOFF to CID?

CID-keyed fonts efficiently handle massive glyph sets — essential for Chinese, Japanese, and Korean typography in professional publishing and prepress.

How do I open a CID file?

Adobe InDesign, Illustrator, and Acrobat Distiller consume CID fonts. FontForge can also inspect and edit CID-keyed font data for development.

What makes CID different from standard fonts?

CID fonts map character IDs to glyphs without encoding limitations, supporting tens of thousands of characters needed for CJK typesetting.

Is CID format still in use today?

Yes, CID-keyed fonts remain standard in Japanese and Chinese prepress and PDF production. Many professional Asian typefaces ship as CID fonts.

Does this conversion cost anything?

No, Convertio provides WOFF to CID conversion completely free of charge. Everything runs online with no software installation.