ZIP Comment Editor
View and edit the archive-level comment stored inside a .zip file's central directory.
What is ZIP Comment?
An editor for the free-text comment field in a ZIP archive. Build systems, updaters and release scripts often stash a version marker there.
How it works
The comment lives in the end-of-central-directory record at the very end of the file, so the archive can be rewritten by patching that record and its trailing bytes. Every entry keeps its original compressed bytes — the operation costs milliseconds regardless of archive size.
- Add your files. Drop files (or a whole folder) onto the drop zone. Browsers hand the contents straight to the page, so nothing is uploaded.
- Choose the options. Pick the format, compression, naming rule or split size. Any change re-computes the preview immediately.
- Download the result. Run the tool and grab the archive, the extracted files or the report. Multi-file results come back as a single .zip.
Examples
A 240 MB photo folder → a 52 MB .zip
JPEGs are already compressed, so the archive only saves 10–15% — but adding the folder structure and a manifest makes the upload verifiable.
A download cut off at 1.4 GB
The File Splitter cuts it into 500 MB chunks that fit the host's limit, and the File Joiner reassembles them, refusing any set with a missing part.
A release bundle with checksums
The Manifest Generator writes sha256sum-style lines next to the files, so the recipient can prove the download arrived intact.
Common mistakes
Expecting ZIP to shrink photos, video or audio
Those formats are already compressed; deflate typically saves single digits on them. ZIP is at its best on text, JSON, CSV, logs and source code.
Treating ZipCrypto as real encryption
Traditional ZIP encryption is legacy and breakable. It stops casual snooping only — for secrets, encrypt the contents with AES-256 first.
Renaming extensions to convert a file
Changing .png to .jpg does not change the bytes inside. Some programs will refuse the file, or display garbage. Use a real converter when the format must change.
Splitting without keeping the suffixes
The parts carry .001, .002 … suffixes on purpose: the joiner orders them by number and fails loudly when one is missing, instead of producing a corrupt file.
Frequently asked questions
What is the difference between an archive comment and a file comment?
An archive comment describes the whole ZIP and is shown in a file manager's properties. Individual entries can carry their own comment inside the central directory; this tool edits the archive-level one, which is what most tools display.
How long can the comment be?
65,535 bytes, a hard limit of the ZIP format. The character counter shows the UTF-8 byte length so multi-byte characters do not sneak past the limit.
Will editing the comment break the archive?
No. Only the trailing record changes; the central directory, entry offsets and every compressed stream stay byte-for-byte identical, so the CRC values remain valid.