Puma (web server)

Puma is an HTTP web server derived from Mongrel and written by Evan Phoenix. It stresses speed and efficient use of memory.

Puma

Original author(s)	Evan Phoenix
Initial release	2011
Stable release	6.6.0[1]  / 28 January 2025; 3 months ago (28 January 2025)
Repository	github.com/puma/puma
Written in	Ruby, C
Operating system	Cross-platform
Available in	English
Type	Web server
License	BSD 3-Clause
Website	puma.io

Reception and use

Puma is the web server shipped with Mastodon^[2] and recommended by the Heroku hosting provider as a replacement for Unicorn.^[3]

Deliveroo published a benchmark comparing the two servers and concluded “Puma performs better than Unicorn in all tests that were either heavily IO-bound or that interleaved IO and CPU work”, but that Unicorn was still slightly better performing in situations where CPU load was the limiting factor.^[4]