The first time you run lnav on a real production log, you see more than you planned to.
Error stacks, system warnings, and — buried inside them — sensitive columns that were never meant to hit your screen raw. Passwords disguised as params. Token strings longer than a JSON field. User data tucked into global debug dumps. You didn’t plan on putting them there, but logs are honest. They keep everything.
Lnav sensitive columns is not just a feature you can skim past. It’s the difference between a tool that exposes you and a tool that protects you. With the right config, Lnav will detect and mask fields you define, shielding private or regulated data while keeping the rest fully readable. No brittle regex in ancient scripts. No duct-taped pipeline filters. The masking happens right where you view the logs, so your data never leaves the source in unsafe form.
You start by identifying the columns you must protect: email, IP, usernames, tokens, payment fields. Then edit your Lnav formats or data source definition. Specify the :hidden or masking rules for those sensitive columns. Lnav applies these consistently across queries, views, and even SQL console outputs. The sensitive data remains in the log file, but it’s never exposed in your terminal. You keep full search and filter power without sacrificing compliance or security.
When this is done well, you can hand log visibility to a teammate without worrying they’ll scroll past a live credential. You can demo a live system without leaking customer info. You can jump into production errors faster because you skip the extra step of sanitizing reports.
And if you want to see masked sensitive columns at work in live queryable logs, there’s no reason to wait. You can load, parse, and safeguard data in minutes. Try it in a real environment at hoop.dev and watch it work before your next deploy.