Read-only · Local comparison

Local file copy checker

Choose an original and its copied file. Compare their contents without uploading them to KYD.

Compare one pair

No files read. Select a pair or try the built-in text demonstration.

SHA-256 · File A

SHA-256 · File B

Identical bytes do not prove a healthy photo, an authentic source or a complete backup. Different bytes can result from conversion or editing.

One precise question

“Are the selected contents exactly the same?” Names, timestamps and thumbnails do not decide the result. The tool compares every byte and independently displays SHA-256 fingerprints.

Compare unmodified originals when that is your preservation goal. A converted JPEG and an original HEIC will not match just because they show the same picture.

Read the result-interpretation guide →

Try before selecting files

Run five image-file experiments without personal files →

The demo compares abc with itself, then with abd. Both are three-byte text fixtures. No personal files are read during the demo.

Privacy boundary

Tool pages prohibit outbound connections from page scripts. The page has no ad script. The browser or operating system may download a cloud placeholder when you select it; choose already-local files if that matters. More privacy details.

For large videos

This is not a batch archive verifier. The browser digest API needs whole inputs in memory, so the 32 MiB limit is intentional. Do not cut or compress an original just to fit this tool.

Reproducible method

Equality is determined by direct byte comparison, not merely equal filenames, file sizes or hashes. Inspect the implementation and test cases. After a match, open the copied media separately in a trusted viewer; this page does not decode it.

Try the image-file experiment

Five controlled comparisons use the same bytes as the downloadable SVG files. No file selection or upload is needed. Results below come from running the comparison, not a preset success message.

Synthetic geometric chart: reference — Reference

Synthetic geometric chart: metadata changed — Metadata changed

Synthetic geometric chart: color changed — Color changed

Original KYD SVG test graphics, not camera photos. The first two use identical drawing instructions; only their metadata differs. No third-party image is used.

Download the files and repeat with the file pickers

reference.svg — 458 bytes. Original geometric test chart.
identical-copy.svg — 458 bytes. Exact copy; only the filename is different.
metadata-change.svg — 458 bytes. One metadata byte changed. Drawing instructions unchanged.
visible-change.svg — 458 bytes. One color byte changed; same byte count, different drawing.
truncated.svg — 200 bytes. Only the first 200 bytes retained; deliberately incomplete XML.

Download SHA-256 reference list · Machine-readable manifest

Read the experiment, interpretations and troubleshooting →

Sources & scope

Source pages checked October 7, 2026. Provider behavior is source-based; examples and the planning method are KYD’s own synthesis, not a hands-on cloud-service test.