Eventide was founded in 1971 by recording engineer Stephen Katz, inventor Richard Factor, and patent attorney Orville Greene in New York City. The company made an immediate impact with the DDL 1745, the first rack-mountable digital delay line, followed in 1975 by the H910 Harmonizer — the world's first commercially available pitch shifter and digital multi-effects processor. The H910 rapidly became a fixture in professional recording studios, its pitch manipulation and doubling capabilities attracting engineers and artists across rock, pop, and experimental music.

Eventide continued developing landmark studio processors throughout the 1970s and 1980s, including the H949 and H3000 Ultra Harmonizer, the latter expanding pitch-shifting and time-stretching into an extraordinarily versatile multi-effects platform. The company also introduced the Instant Phaser, Instant Flanger, and Omnipressor, cementing its reputation as a pioneer in digital signal processing. Eventide later extended their algorithms into software plugins, and entered the stompbox market with the Factor pedal series — the TimeFactor, ModFactor, PitchFactor, and Space — bringing studio-grade effects processing to live performance rigs.

Eventide's processors have appeared on a vast number of commercial recordings, film scores, and broadcast productions. The H910 Harmonizer gained particular notoriety for its use by artists including Jimmy Page, Frank Zappa, and Eddie Van Halen, and was used to craft the voice of R2-D2 in Star Wars. Headquartered in Little Ferry, New Jersey, the company produces hardware processors, guitar and bass pedals, and software plugins used in professional recording studios and live performance setups worldwide.

Eventide has 126 products cataloged on Equipboard, including Effects Processors, Reverb Plugins, and Multi Effects Pedals. Their gear is featured by 730 artists, with the strongest followings in Rock, Electronic, and Pop. Notable users include Richard Devine, Sugizo, and Matt Lange. Eventide's catalog spans the full price spectrum — from entry-level options to high-end flagships.