Log Level Filter
Isolate ERROR / WARN / DEBUG lines from noisy logs with one-click level toggles.
About Log Level Filter
Log Level Filter isolates ERROR, WARN, DEBUG and other severity lines from a noisy log with one-click toggles, and counts how many of each level appear — perfect for late-night debugging.
How to use Log Level Filter
- 1Paste or type your data into the input box above (a sample is pre-filled so you can try it instantly).
- 2Adjust any options on offer — delimiter, columns, formatting and so on — to match what you need.
- 3Filtering happens instantly as you type; review the result in the output panel.
- 4Click Copy to grab the output or Download to save it as a file — Log Level Filter keeps everything on your device.
Why use Log Level Filter?
- ✓Pulling only errors out of a huge log dump
- ✓Counting warnings and errors in a deploy log
- ✓Sharing just the relevant lines with a teammate
- ✓100% free with no sign-up, no watermark and no usage limits
- ✓Runs entirely in your browser — your data is never uploaded or stored
- ✓Works offline once loaded, with instant results and one-click copy or download
Frequently asked questions
Which levels are recognised?+
TRACE, DEBUG, INFO, WARN, ERROR and FATAL — matched as whole words anywhere in each line, with a live count per level.
What if I select no levels?+
With no level selected, every line passes through unchanged, so you can use it purely to see the per-level counts.
Is it free to use?+
Yes — it is completely free with no sign-up, no account and no usage limits. There is no watermark and no paywall, so you can process as many files as you like.
Is my data private and secure?+
Yes. This tool runs entirely in your browser using client-side JavaScript — your data is never uploaded to a server, stored or logged. Once the page has loaded you can even use it offline, which makes it safe for confidential or proprietary files.
Related converters & parsers
Related Data tools
Text to EPUB Converter
Turn plain text or a manuscript into a valid EPUB ebook — chapters, metadata and all — entirely in your browser.
● LiveMarkdown to EPUB Converter
Convert a Markdown manuscript into an EPUB 3 ebook, splitting chapters on level-1 headings. No upload.
● LiveHTML to EPUB Converter
Build a clean EPUB ebook from HTML articles or web-page exports, with optional chapter splitting.
● Live