About GrepBoard Log
GrepBoard Log is a log analyzer for the moment something is on fire and you have a log file in front of you. It is part of grepboard.com, a small set of tools for people who read logs, configs and command output for a living.
What it is built around
- Nothing leaves the browser. Not as a promise: the page is served with a Content-Security-Policy that blocks every outgoing request, and you can check that in DevTools.
- Results first. A card title says what was found ("5xx 174 — 82% on /api/upload"), not what the chart is ("Status code distribution").
- Every number comes with the shell command that reproduces it, so the board can be checked on the server and the commands can be reused.
- Format guides are written from the official documentation, and from the source code that writes the lines where the documentation is silent.
A card and its command, as you would see it on the board:
$ grep -E '" 5[0-9]{2} ' access.log | awk '{print $7}' | sort | uniq -c | sort -rn | head
3 /api/uploadHow it is made
The analysis core is written in Rust and compiled to WebAssembly. It runs in a Web Worker so the page stays responsive while large files stream through. The site is static files only; there is no server-side code and no database.
log.grepboard.com carries no ads and no analytics, and will not: the same Content-Security-Policy that keeps logs in the browser keeps third-party scripts out.
Guides
Field-by-field guides with tested one-liners: nginx, Apache, HAProxy (timers and termination states), MySQL slow query log, auth.log, syslog, and custom formats.
FAQ
Who is it for?
Infrastructure, SRE and backend engineers who need to read an access log, a load balancer log or a system log quickly, often during an incident.
How is it free?
The page is static files served from a CDN, so running it costs almost nothing. There is nothing to sell from your data, because the page never receives it.
Can I use it offline or on an isolated network?
Once the page has loaded it works without a network connection.