Nature of Business	12 Months Ended
Dec. 31, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Nature of Business	Nature of Business Fastly, Inc. has built an edge cloud platform that can process, serve, and secure its customer’s applications as close to their end users as possible. Our edge network spans 68 Points-of-Presence ("POPs") across 53 markets, as of December 31, 2019. We were incorporated in Delaware in 2011 and are headquartered in San Francisco, California. As used herein, "Fastly," "we," "our," "the Company," and similar terms include Fastly, Inc. and its subsidiaries, unless the context indicates otherwise. Stock Split On May 3, 2019, we implemented a 1-for-2 reverse stock split of our stock. All shares of common stock, stock-based instruments, and per-share data included in these financial statements give effect to the stock split and the changes in authorized shares have been adjusted retroactively for all periods presented. Initial Public Offering ("IPO") On May 21, 2019 we completed an IPO in which we sold 12,937,500 shares of our newly authorized Class A common stock, which included 1,687,500 shares sold pursuant to the exercise by the underwriters of an option to purchase additional shares, at the public offering price of $16.00 per share. We received net proceeds of $192.5 million, after deducting underwriting discounts and commissions, from sales of our shares in the IPO. The net proceeds include additional proceeds of $25.1 million, net of underwriters' discounts and commissions, from the exercise of the underwriters' option to purchase an additional 1,687,500 shares of our Class A common stock. Prior to the closing of the IPO, all shares of common stock then outstanding were reclassified as Class B common stock. Immediately upon the closing of the IPO, all shares of convertible preferred stock then outstanding were converted into 53,630,213 shares of Class B common stock on a one-to-one basis.

Nature of Business

12 Months Ended

Dec. 31, 2019

Organization, Consolidation and Presentation of Financial Statements [Abstract]

Fastly, Inc. has built an edge cloud platform that can process, serve, and secure its customer’s applications as close to their end users as possible. Our edge network spans 68 Points-of-Presence ("POPs") across 53 markets, as of December 31, 2019. We were incorporated in Delaware in 2011 and are headquartered in San Francisco, California.

As used herein, "Fastly," "we," "our," "the Company," and similar terms include Fastly, Inc. and its subsidiaries, unless the context indicates otherwise.

Stock Split

On May 3, 2019, we implemented a 1-for-2 reverse stock split of our stock. All shares of common stock, stock-based instruments, and per-share data included in these financial statements give effect to the stock split and the changes in authorized shares have been adjusted retroactively for all periods presented.

Initial Public Offering ("IPO")

On May 21, 2019 we completed an IPO in which we sold 12,937,500 shares of our newly authorized Class A common stock, which included 1,687,500 shares sold pursuant to the exercise by the underwriters of an option to purchase additional shares, at the public offering price of $16.00 per share. We received net proceeds of $192.5 million, after deducting underwriting discounts and commissions, from sales of our shares in the IPO. The net proceeds include additional proceeds of $25.1 million, net of underwriters' discounts and commissions, from the exercise of the underwriters' option to purchase an additional 1,687,500 shares of our Class A common stock. Prior to the closing of the IPO, all shares of common stock then outstanding were reclassified as Class B common stock. Immediately upon the closing of the IPO, all shares of convertible preferred stock then outstanding were converted into 53,630,213 shares of Class B common stock on a one-to-one basis.