or click to choose. Rotated logs like app.log.1, .txt and .out files work too.
Add log files to compress them. You’ll see the savings and a preview with errors and warnings highlighted.
Compressed entirely in your browser. Your logs are never uploaded.
This LOG file compressor shrinks server, app and system logs into standard .gz, .zip or .tar.gz files, usually 85–95% smaller than the original. It also gives you a quick read of what’s inside: how many errors and warnings each log has, the time range it covers, and a preview with problem lines highlighted. Everything happens in your browser, so logs with IP addresses, user data or tokens never leave your computer.
How to compress log files
- Drop your log files onto the left box, or click it to choose them. You can add as many as you like, including rotated logs like
access.log.1. - Pick a format and compression level. Compression starts right away and updates if you change a setting.
- Check the Results tab for the savings, or Preview to see the first lines and every error and warning the tool found.
- Download each file, or all of them as one archive.
Which format should I use?
| Format | Best for | Open with |
|---|---|---|
.gz | Single logs, and the format logrotate, servers and log tools expect. You can read it without unpacking using zcat, zless or zgrep. | Linux and macOS built in, 7-Zip on Windows |
.zip | Sending several logs to someone on Windows or Mac, or attaching them to a support ticket. | Built into every OS |
.tar.gz | Bundling many logs for Linux servers, backups and archives. Compresses better than .zip when files are similar. | tar -xzf, macOS, 7-Zip |
Balanced is the right level almost every time. Smallest squeezes out a few more percent and takes longer on big files. Fast is handy for very large logs when speed matters more than size.
The clean-up options
By default the tool is lossless: unpacking the archive gives you back the exact original file, byte for byte. The clean-up options change the log’s content before compressing, so only use them on copies you don’t need to keep in full.
- Strip color codes removes the ANSI escape sequences (like
^[[31m) that colorize terminal output. They clutter logs opened in an editor. - Remove blank lines deletes empty lines.
- Collapse repeated lines replaces runs of identical lines with one copy and a note like
[previous line repeated 41 more times]. - Drop DEBUG & TRACE removes debug-level lines and any indented stack trace lines under them, which can cut a verbose log in half.
Why log files compress so well
Logs repeat themselves constantly: the same timestamps formats, IP addresses, URLs, log levels and messages appear on line after line. Compression stores each repeated pattern once and then refers back to it, so a 500 MB access log often ends up 25–50 MB. Logs that are mostly random IDs or hashes compress less, usually around 60–80%.
Is it safe for production logs?
Yes. Files are read and compressed inside your browser, and nothing is uploaded or stored. That matters for logs, which often hold IP addresses, email addresses, session tokens and other data you shouldn’t paste into random websites. Large files work too, since they’re processed a piece at a time instead of all at once.
Frequently asked questions
How do I open a .log.gz file?
On Linux or macOS, run gunzip app.log.gz, or read it in place with zless app.log.gz. On Windows, open it with 7-Zip or WinRAR. Most log viewers can open .gz logs directly.
Is there a file size limit?
There’s no fixed limit. Files are processed in chunks, so even logs of several hundred megabytes work on most computers. Archives over 4 GB aren’t supported in .zip format.
Can I compress files that aren’t .log files?
Yes. Any plain text file works, including .txt, .out, .err, .csv and .json logs. Files that are already compressed (.gz, .zip, .7z and similar) are skipped, since compressing them again saves nothing.
How does it count errors and warnings?
It looks for standard log levels near the start of each line, like ERROR, WARN, [error] or "level":"warn", in common formats such as syslog, Apache, Nginx, Log4j, Python logging and JSON logs. The counts are a quick guide, not a full log analysis.
Will the compressed file keep the original name?
Yes. app.log becomes app.log.gz, and the original name is stored inside the .gz so it unpacks to the same name.