FAQ

What metadata is, what gets removed, and why nothing ever leaves your device.

The basics

What is metadata?: Hidden information stored inside a file alongside the visible content: where a photo was taken, which phone took it, when it was created, which app edited it, and sometimes the account name of the person who made it.
What does NullMeta remove?: Location (GPS coordinates, altitude, GPS time), device data (camera make and model, lens, serial numbers, exposure settings), dates and times, software and author tags (editing app, artist, copyright, comments, XMP and IPTC records), plus other embedded blocks such as colour profiles and text chunks. You choose which of these go.
Does the image itself change?: In normal mode, no. NullMeta rewrites only the metadata blocks and leaves the compressed pixel data byte-for-byte identical, so there is zero quality loss. Aggressive mode re-encodes the image instead, which wipes everything including unknown blocks, at the cost of a small quality and size change on JPEG.

Do my files leave my device?: No. All reading and rewriting happens in this browser tab using local JavaScript. There is no upload endpoint, no server-side processing and no analytics on your files. You can disconnect from the internet and it still works.
How can I verify that?: Open your browser's developer tools, go to the Network tab, and clean a file. You will see no outgoing requests carrying your data. You can also install NullMeta as an app and use it fully offline.
Do you store anything?: Only your theme choice, in your own browser's local storage. No accounts, no cookies for tracking, no file history.

Which files are supported?: JPG/JPEG, PNG, WEBP, GIF, PDF, ZIP and JAR. Drop a folder and everything supported inside it is picked up automatically.
How are PDFs handled?: The document information — title, author, subject, keywords, producer, creator application, creation and modification dates — is cleared according to your selection, and the document-level XMP metadata stream is dropped in aggressive mode. Text and images inside the pages are untouched, so anything visibly printed on the page stays.
How are ZIP and JAR files handled?: The archive is unpacked and repacked with every entry's timestamp neutralised, and archive comments and extra fields are dropped. Files inside the archive are not individually cleaned.
What can't be removed?: Anything that is part of the visible content: a licence plate in a photo, a name printed in a document, a watermark. Metadata baked into a proprietary container inside the pixel data (some raw camera formats) is also out of scope.

What does 'randomize timestamps' do?: Instead of setting every date to the same fixed value, each file gets its own random past date. A fixed date makes it obvious that files were cleaned together; random dates break that link.
When should I use aggressive mode?: When a file comes from an unknown source and you want certainty over fidelity. It rebuilds images pixel-by-pixel, so nothing hidden in an unusual block can survive — but JPEG is re-compressed and colour profiles are dropped.
Can I use it offline?: Yes. NullMeta can be installed from your browser's menu ('Install app' or 'Add to Home Screen') and then works with no connection at all.