Founded in 2009 by David Rainger in North West London, Rainger FX is a boutique guitar effects pedal company known for unconventional, experimental designs that push the boundaries of what stompboxes can do. David Rainger's background as a recording studio engineer, music journalist, and pedal reviewer informs the company's approach: pedals that prioritize inspiring sounds, reliability, and an element of playful interaction. The company has launched over 30 different products, all designed and built in the UK.

A defining feature of many Rainger FX pedals is the Igor pressure pad — a lightweight, pressure-sensitive expression controller that replaces bulky rocker-style expression pedals. Originally created as a companion to the now-discontinued Dr Freakenstein Fuzz, Igor allows players to manipulate effects parameters in real time using foot or hand pressure, and ships bundled with several of the company's pedals. Among the most distinctive offerings is the Minibar Liquid Analyzer, an overdrive/fuzz pedal whose tone is shaped by the conductivity and opacity of whatever liquid the player pours into a built-in watertight chamber. Other notable pedals include the Razor Fuzz, which uses "virtual plectrum" technology to digitally model the attack characteristics of picks made from materials like sandpaper and metal; the Drone Rainger, a dual-pitch drone and delay unit; and the Snare Trap, an analog/digital hybrid drum machine that players can trigger through their guitar signal.

Rainger FX pedals have found their way onto the pedalboards of artists spanning rock, electronic, and experimental music, including Billy Gibbons, John Frusciante, Noel Gallagher, FINNEAS, Fred again.., Mk.gee, Vernon Reid, Nels Cline, Joe Bonamassa, and Carlos Alomar.

Rainger FX has 31 products cataloged on Equipboard, including Fuzz Effects Pedals, Guitar Synth Pedals, and Multi Effects Pedals. Their gear is featured by 28 artists, with the strongest followings in Rock, Electronic, and Pop. Notable users include Vernon Reid, Isaac Brock, and Carlos Alomar. Rainger FX's catalog spans the full price spectrum — from entry-level options to high-end flagships.