Short answer
When Sora 2’s API was available, a single generated clip could be up to 20 seconds long. OpenAI’s March 2026 API guide listed duration options of 4, 8, 12, 16, or 20 seconds, with 4 seconds as the default. The guide is now marked as archived, so those figures describe the documented API capability—not a service you can use today. (developers.openai.com)
As of November 9, 2026, Sora is discontinued: OpenAI says its web and app experiences ended on April 26, 2026, and its API was discontinued on September 24, 2026. So there is no current Sora 2 generation limit to use in production; the service is no longer available. (help.openai.com)
Was the limit the same in the app and API?
The 4-, 8-, 12-, 16-, and 20-second options come from OpenAI’s archived API guide. They should not be treated as a verified app or web limit. OpenAI’s discontinuation notice confirms when the consumer experiences ended, but does not specify their former maximum clip length. (developers.openai.com)
Could a finished video be longer than one generation?
A longer edited video can be assembled from multiple clips, but that does not make any individual generation longer. OpenAI’s archived guide also described extending an existing video; the documentation retrieved here does not establish a maximum total runtime for an extended video. Because the Sora API has since been discontinued, neither the old generation settings nor extension workflow should be treated as currently available. (developers.openai.com)
Sources
Sora 2 Prompting Guide — OpenAI Developers
What to know about the Sora discontinuation — OpenAI Help Center