Twilio was founded in 2008 by Jeff Lawson, Evan Cooke, and John Wolthuis[4] and was based initially in Seattle, Washington, and San Francisco, California.

[5] On November 20, 2008, the company launched Twilio Voice, an API to make and receive phone calls completely hosted in the cloud.

[12] In July 2015, Twilio raised a $130 million Series E from Fidelity, T Rowe Price, Altimeter Capital Management, and Arrowpoint Partners, in addition to Amazon and Salesforce.

[22] In December 2023, Twilio announced its decision to reduce its workforce by 5%, affecting around 300 employees, primarily within its Data and Applications division.

[24] An early example is GroupMe, which was founded in May 2010 at the hackathon of TechCrunch Disrupt and uses Twilio's text messaging product to facilitate group chat.

[2] Later that year in July, alleged threat actors acquired the phone numbers of over 33 million users of the company's multi-factor authentication service "Authy".

[30] In February 2015, Twilio acquired Authy, a Y Combinator–backed startup that offers two-factor authentication services to end users, developers and enterprises.

[34] In October 2018 of that same year Twilio announced they were acquiring SendGrid, a Denver, Colorado-based customer communication platform for transactional and marketing email, for $2 billion.

[47] Rather than using industry-standard protocols such as SIP for call control, Twilio uses a customized markup language known as TwiML to allow for direct integration with its services.