When I cannot work out what language your code is, the result now says so instead of quietly pretending it is C, and offers you a button to send that snippet in with the language name. I use those to write new detection rules, so the next person who pastes the same sort of thing gets it right.
It is entirely up to you: nothing is sent unless you click the button, and the privacy note spells out exactly what happens to it if you do.
2026-08-21: The languages you actually paste now auto-detect
I have been watching the (anonymous) usage stats for a month now, and it turns out a fair few of the most-pasted languages could not be recognised automatically, so you had to pick them from the list every time. Fixed: Batch files, MySQL, R, Verilog, JavaCC, Windows Script Files and Groovy Server Pages now all auto-detect from the pasted code alone. Everything in the top 25 that reasonably can be detected now is.
While I was at it, every popular language now has example code on the languages page too.
2026-07-25: A filter shortcut and a fix for the HTML+CSS output
A few small ones:
Ctrl+S jumps straight to the "Filter types" box so you can find a language without reaching for the mouse (the underlined "s" is the hint).
Fixed the HTML + CSS classes output, which had a stray "Created with colorer library" line stuck at the very top. It comes back clean now.
Libre Computer Sweet Potato Review: $45 SBC with 4K Support - Worth It?
[26:21] A $45 single board computer (SBC) powered by the Amlogic S905X processor with four ARM Cortex-A53 cores. This Raspberry Pi alternative features 2GB DDR4 RAM, 4K video decoding, UEFI bootloader support, USB Type-C power delivery, and optional PoE connectivity, making it an intriguing budget option for makers and hobbyists.