Before uploading

Check this device first.

This check uses a few synthetic bytes on your device. It does not select photos, open your library, or contact file storage.

Important limitYour phone's picker may create temporary files. A web page cannot promise uploads with zero free space. Originals are not compressed or transcoded. This page only checks locally and never uploads files.

Local chunks and encryption

Checks a secure context, Blob chunk reads, WebCrypto AES-GCM, byte-for-byte recovery and a local non-extractable signing key. It does not save your recovery code or decryption key.

Not checked yet.

Local selected-file format check

Optionally select a few files. Only the first 32 bytes of each are read to compare size, extension and JPEG/PNG/HEIC signatures. No full photo is read, previewed, encrypted or uploaded. Passing does not prove the phone picker supplied the camera original.

Choose files for a local check

No files selected.

The phone picker may create temporary files, so this does not work with guaranteed zero free space. Never delete your local originals based on this check.

Before launch, specific browsers still need real-device low-space, original-source, and save-and-recover testing. Passing this check never means you can delete phone photos.

See availability →