Extract text from Obfuscated OpenType fonts (ODTTF)
To convert ODTTF fonts to another format, you need Microsoft XPS Viewer or other Font software.
To convert other file formats to the "Obfuscated Font File" file type, you need software like Microsoft XPS Viewer or a similar tool.
The .odttf file extension stands for Obfuscated OpenType Font. It is a proprietary, obfuscated font format primarily used within XML Paper Specification (XPS) documents, EPUB files, and modern Microsoft Office documents. These files embed custom typography into a document so that it displays perfectly across different devices, while simultaneously preventing users from legally or technically extracting the font for personal use.
These files are not meant to be opened directly. They are processed internally in the background by readers like Microsoft XPS Viewer or standard EPUB readers when rendering a document on the screen. The underlying format is identical to standard OpenType, but with an intentionally scrambled header.
The main disadvantage of an .odttf file is its intentional corruption. To prevent copyright infringement, the first 32 bytes of the font file are scrambled using a basic XOR operation tied to the document's internal GUID. Because of this, you cannot simply extract the .odttf file and install it on Windows or macOS. Standard design applications like Adobe Illustrator will reject it as a broken or invalid file.
Users typically need to convert .odttf files back to standard TTF (TrueType Font) or OTF (OpenType Font) to install and use the typography system-wide. For web embedding, converting to WOFF or WOFF2 is recommended. During this de-obfuscation process, no graphical quality or vector data is lost.
Reversing this obfuscation is a challenge. Because the file header is scrambled, standard online font converters fail entirely - they cannot read the broken metadata. Our tool will identify the file format, inspect its internal structure, and show text or internal content. If our analysis detects an extractable obfuscation key or a supported embedded format, viewing or conversion to a standard font may still be possible.
Convert.Guru analyzes your ODTTF file, detects the exact format, and lets you read the text inside.
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If you want to convert ODTTF file to , you can use Microsoft XPS Viewer or similar software from the "Obfuscated Font Embedding" category. In the File menu, look for Save As… or Export….
To convert files to ODTTF, try Microsoft XPS Viewer or another comparable tool in the "Obfuscated Font Embedding" category.
The history of Convert.Guru began over 25 years ago in California with Tom Simondi’s file-format database. A former contributor to Space Shuttle development and a software pioneer of the 1980s, Simondi established a trusted resource for file type analysis that was even referenced by Microsoft Windows XP. Today, we use modern technology to process and convert thousands of file formats while continually improving our ODTTF converter.