01
ZIP File Creator
Packs any set of files into a single .zip archive inside your browser, with a choice of…
Gzip Compressor
Compresses text or a file to gzip, deflate or raw deflate using the browser's built-in compression, with the size saved shown.
Developer
Nothing uploaded
No sign-up
Free, unlimited
Drop a file, or just paste text belowcompression happens in the page — nothing is uploaded
Add a file to begin.
In short
Gzip Compressor is a free online tool on inputtesthub.com that compresses text or a file to gzip, deflate or raw deflate using the browser's built-in compression, with the size saved shown. It needs no account, no download and no payment, and there is no daily usage limit. Everything is processed inside your own browser, so the data you paste is never uploaded to a server.
How to use the Gzip Compressor
- Drop a file, or paste text.
- Choose gzip unless you know you need one of the others.
- Compress, and download the result.
About the Gzip Compressor
The Gzip Compressor compresses text or a file to gzip, deflate or raw deflate using the browser's built-in compression, with the size saved shown. It runs as plain JavaScript inside the page, which means there is no upload step, no queue and no size limit imposed by a server — the only limit is your own device.
What people use it for
- Making a .gz to test what a server will actually send.
- Compressing a log file before attaching it to a ticket.
- Seeing what a payload costs on the wire.
Details
| Engine | CompressionStream — built into the browser, no library |
|---|---|
| gzip | The .gz from the command line; header plus CRC32 |
| deflate | zlib-wrapped, as used inside .zip and by HTTP |
| deflate-raw | No header or checksum at all |
| Brotli | Not offered — it is not a CompressionStream format |
The maths behind it
This tool uses the browser's native CompressionStream, which is the same DEFLATE implementation the platform uses for HTTP — no library is loaded. Every intermediate value is shown on screen, so the result can be checked by hand.
Gzip compresses a stream, not a folder: it stores no filenames and holds exactly one thing. That is precisely why the command line pairs it with tar as
.tar.gz — tar makes the many-files-into-one archive, gzip shrinks the result. If you want a package you can list and extract from, use the ZIP Creator instead.Where this tool stops
One file or one block of text at a time. There is no tar step, so this cannot produce a .tar.gz.
Frequently asked questions
What is the difference between gzip, deflate and deflate-raw?
The same compression under three different wrappers. Raw deflate is the compressed data alone. Deflate adds a two-byte zlib header and an Adler-32 checksum. Gzip adds a ten-byte header with an optional filename, and a CRC-32. That is the whole difference, and it is why a file compressed as one will not open as another.
Why is there no Brotli option?
Because the browser does not offer it. <code>CompressionStream</code> supports gzip, deflate and deflate-raw only. Brotli would mean shipping a WebAssembly build of the encoder, and a page that implied it was native when it was not would be misleading about both size and speed.
Why did my file get bigger?
It was already compressed. Gzip adds an eighteen-byte header and trailer, and if it finds no redundancy to remove, that is all you get — a slightly larger file. JPEG, MP4, PDF and .zip all behave this way.
Is the Gzip Compressor free, or is there a paid tier?
Free, unlimited, and no email address required. You can use it a hundred times a day and nothing changes.
Is the Gzip Compressor safe to use with private information?
No. The Gzip Compressor runs entirely in your browser using JavaScript. Your input never reaches inputtesthub.com or any third party — open your browser's Network tab while you use it and you will see no request go out.
How is the result calculated?
It uses the browser's native CompressionStream, which is the same DEFLATE implementation the platform uses for HTTP — no library is loaded. The full working is printed under the result, so you can follow every step rather than trusting a black box.
What do people use the Gzip Compressor for most?
The jobs it is built for: making a .gz to test what a server will actually send. Compressing a log file before attaching it to a ticket. Seeing what a payload costs on the wire. It is built for exactly those cases rather than being a general-purpose tool with this bolted on.
Is there anything the Gzip Compressor cannot do?
One file or one block of text at a time. There is no tar step, so this cannot produce a .tar.gz. Knowing where a tool stops being trustworthy matters more than the cases where it works.
What figures does the Gzip Compressor work from?
Engine is CompressionStream — built into the browser, no library. gzip is The .gz from the command line; header plus CRC32. deflate is zlib-wrapped, as used inside .zip and by HTTP. These are printed on the page itself, so you do not have to take them on trust.
Is there a file size limit?
There is no limit set by us, because your file is never uploaded — the only ceiling is the memory your own browser will give the tab. Very large files simply take longer to process, and a phone will give up sooner than a desktop.
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