ToolJovia
Files

Guarded File Byte Patch

Check expected original bytes and optional SHA-256 before downloading a separate equal-length patched copy.

✓ Browser-local processing
Files are read locally and are not uploaded.

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How to use Guarded File Byte Patch

Make a small, explicit binary edit without silently changing an unexpected file version. Every patch names an exact zero-based byte offset, expected bytes and replacement bytes; all guards are verified against the unchanged original before a separate copy is allocated.

  1. Enter local file, equal-length guarded patches json, optional required original sha-256.
  2. Choose the settings for guarded file byte patch, then run the tool.
  3. Review the result and any limitations before copying or downloading it.

Good to know

  • Original file at most 1 MiB; 100 patches, 2,048 bytes per patch and 50,000 patch JSON characters. Original offset numeric spellings must represent exact bounded integers. Non-changing, overlapping, out-of-file and unequal-length patches are refused.
  • Binary copy only; no execution, format repair, checksum repair, signature validity or safe-to-open promise. All bytes remain untrusted. A hash is a content guard, not authenticity; the source file is never overwritten.
  • Processing is local. Output is limited to 1,000,000 text characters unless a stricter file limit is stated.

Common questions

Does a successful patch mean the file will still open?

No. Byte replacement can break the file format, checksums or signatures. The tool proves only that the supplied original-byte guards matched and the declared equal-length changes were applied to a separate copy.

Is this input sent to a server?

No. The application processes this input inside your browser tab and does not save it to persistent storage.

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