Extract text from OmniOutliner 3 documents (OO3)
To convert OO3 documents to another format, you need OmniOutliner or other Text software.
To convert other file formats to the "Outliner Document" file type, you need software like OmniOutliner or a similar tool.
The .OO3 file extension is used for documents created by OmniOutliner 3, a popular outlining and brainstorming application developed by The Omni Group exclusively for macOS and iOS.
Users typically rely on OmniOutliner to open and edit these files. Under the hood, .OO3 files are not actually single files; they are macOS package directories containing an XML file (usually named contents.xml) and an attachments folder. Because it is a proprietary, Apple-centric package format, Windows and Linux users cannot open .OO3 files natively. They require an active, paid license to OmniOutliner. If you receive an .OO3 file and do not have a Mac, you are essentially locked out of the data. Furthermore, standard online converters fail to process them because web browsers expect flat binary files, not macOS directory structures.
To share these outlines universally, you must export them from the original software to standard formats like OPML (Outline Processor Markup Language), PDF, RTF, or TXT. Since .OO3 is a closed format, true conversion usually requires the original software. However, convert.guru can inspect the uploaded package, extract the internal XML data, and recover your underlying text so you are not left stranded.
Convert.Guru analyzes your OO3 file, detects the exact format, and lets you read the text inside.
Users also converted XML files.
If you want to convert OO3 file to CSV, JSON, XML, YAML, YML, TOML, INI, CFG, CONF, DAT, DB or SQL, you can use OmniOutliner or similar software from the "Hierarchical Outline Storage" category. In the File menu, look for Save As… or Export….
To convert DBF, XML, SQLITE, XLSX, SQL, TSV, ACCDB, YAML, MDB, CSV, ODS or JSON files to OO3, try OmniOutliner or another comparable tool in the "Hierarchical Outline Storage" 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 OO3 converter.