7Z to GZ converter
Your 7Z goes in and a GZ comes out. GZ is the usual choice for HTTP Content-Encoding for text, HTML, CSS and JavaScript. The practical difference is that the result opens anywhere, which 7Z files do not. Your file never leaves your computer.
How to convert 7Z to GZ
- 1 Drop your 7Z .7z file onto the page, or click to browse for it.
- 2 Check the options. Nothing is thrown away on the way to GZ, so there is no quality dial to set.
- 3 Convert. The work happens on your own machine, so how long it takes depends on your computer and the file.
- 4 Download the GZ, or add more files and do the whole set in one go.
Why convert 7Z to GZ
- A 7Z will not open in a browser, so anything going onto a web page, into a document or into a message has to become a GZ first.
- Very fast to compress and decompress, with modest memory use.
- Decoded natively by every browser as part of HTTP transfer encoding.
- Compressing individual log files during rotation.
- 7Z: solid blocks mean extracting one file may decompress a whole group.
7Z compared with GZ
How the two formats differ on the things that decide whether a conversion is worth making.
| Property | 7Z | GZ |
|---|---|---|
| File extension | .7z | .gz |
| Multiple pages | Yes | No |
| Colour depth | LZMA and LZMA2 with solid blocks, optional AES-256 | DEFLATE (LZ77 plus Huffman), CRC32 integrity trailer |
| Browser support | No browser support | Every browser |
| Introduced | 1999 | 1992 |
| Developed by | Igor Pavlov | Jean-loup Gailly and Mark Adler |
Quality and what changes
Both sides are lossless, so every pixel survives the trip intact and converting back returns the same image. What changes is the size and what the file can carry: GZ compresses the same data with a different algorithm, so the size can move in either direction.
- 7Z files can be read here but not created, so conversions run one way only.
- A multi-page 7Z produces one GZ per page.
- One GZ limitation to keep in mind: decompression is strictly sequential, so seeking into it is expensive.
Questions about 7Z to GZ
What happens to a multi-page 7Z?
GZ holds one page, so each page becomes a separate file and you get the set as a ZIP. Nothing is discarded, it just cannot stay in a single document.
Is my 7Z file uploaded anywhere?
No. The whole thing runs inside the browser tab you already have open. Your 7Z is read straight from your own disk, converted on your machine and handed back as a GZ. Nothing is sent anywhere, nothing is stored and there is no account.
Is there a file size limit?
There is no server-side limit because no server sees the file. The real ceiling is your device memory, since the input and the output both have to fit in the tab. A few hundred megabytes is usually fine on a desktop machine and considerably less on a phone.
Can I convert several 7Z files at once?
Yes. Add as many as you like and they are processed one after another, then offered as separate GZ downloads or as a single ZIP. Speed depends on your own processor rather than on a queue.
Does the converter work offline?
Yes, after the page has loaded once. The engine is cached by the browser, so you can disconnect, reload and keep converting. That falls out of doing the work locally rather than being a separate mode you switch on.