File handoff manifest

Generate a SHA-256 file manifest with exact byte sizes and optional generic filenames, then verify selected files against it locally.

Generate or verify SHA-256 hashes and exact byte sizes for up to 100 files totalling 64 MiB. Verification matches file contents even if filenames changed. A match does not prove sender identity.

Operation Files to hash or verify Use generic names in the generated manifest

Generic names affect the manifest only. Source files are not renamed. Otherwise, unsafe characters are replaced and duplicate filenames receive a number.

Manifest for verification (JSON, up to 128 KiB)

Check a handoff by its contents

The browser records a SHA-256 hash and exact byte size for every selected file. Duplicate names receive numbers in the manifest; generic names can replace all source names. Source files themselves are not renamed or changed.

Verification matches files by size and hash, so a changed filename does not break a valid handoff. Every manifest entry requires a matching selected file. Duplicate contents are counted separately. A missing or changed file produces a mismatch report.

A matching manifest is evidence that these bytes agree with that manifest. It does not prove who created or sent the files. An attacker replacing both the files and the manifest can generate matching hashes. Manifests also reveal file sizes and hashes, which can identify known files.