A photo from a phone carries far more than the picture: where it was taken to within a few metres, when, on which camera, and often a small embedded copy of the original. This redraws the image from its pixels alone, so none of that survives into the saved file. What it does not do is change anything you can see — if the street sign is in the frame, it is still in the frame.
This page loads no libraries at all — the work is done by the browser itself. Your file is read on your own machine and never sent anywhere — open your browser's network tab and watch while you use it.
Everything that is not pixels: GPS coordinates, date and time, camera make, model and serial number, lens, exposure settings, editing history, colour profile and the embedded thumbnail. The file is rebuilt from the decoded image, so rather than deleting known fields it simply never writes any of them.
Because it is a copy of the picture as it was, and it does not always get updated when the image is edited. There are well-known cases of a photo being cropped or a face being covered while the thumbnail kept the original view. Rebuilding the file from the pixels removes that possibility entirely rather than hoping the editor refreshed it.
No. The pixels are drawn through unchanged. Metadata removal is about what is hidden in the file, not about what is visible in the image — if something in the frame should not be published, this tool cannot help with that and does not claim to.
Usually smaller for a phone photo, because the metadata block and the thumbnail can run to tens of kilobytes. Saving as JPEG re-compresses the picture, which loses a little quality; PNG keeps every pixel exactly but produces a much larger file.
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