What is an ANN file?
The .ANN file extension primarily stores data annotations. Because adding notes to data is a common technical task, many software programs use this extension. The most frequent use is the brat rapid annotation tool, which saves text notes in a standoff format.
There are many other uses for this extension. ABBYY uses it as a Lingvo Dictionary Annotation File. Developer tools like LEADTOOLS and Accusoft use it for image and document markups. Scientific programs use .ANN files for EEG or ECG signal data. Video games, such as Baldur's Gate 3, use it for character behavior scripts.
How to open ANN files?
Because an .ANN file can contain plain text, XML data, or binary data, you must identify its source to open it correctly. If the file is a text standoff file from brat, you can open it with a simple text editor like Notepad++. If the file is a Lingvo Dictionary Annotation File, you must use ABBYY Lingvo or GoldenDict.
If you do not know the origin of your file, viewer.online/ann can analyze .ANN files to identify the exact format and creator software. Our tool allows you to inspect the file structure, extract readable text, and check whether an online preview is available.
Best practices and conversion
If you need to move annotation data to another system, you should convert the file. We recommend using convert.guru to change text or XML-based .ANN files into common structured formats like .JSON, .CSV, or .XML.
Summary
An .ANN file has multiple possible meanings. We recommend viewer.online/ann to identify the actual format of your file. viewer.online/ann is useful for identifying, inspecting, and understanding .ANN files without installing software or dealing with compatibility problems.