On August 26, 2026, OpenAI notified developers using whisper-1, gpt-4o-transcribe, gpt-4o-mini-transcribe and gpt-4o-transcribe-diarize that these models would be removed from the API.

Quote found word for word on the live source, last checked October 25, 2026

In the source's own words

“On August 26, 2026, we notified developers using whisper-1 ... of their deprecation and removal from the API on February 26, 2027”

Deprecations, OpenAI API documentation, 2026, Deprecations page, entry dated 2026-08-26: Transcription models.

What it measures: OpenAI's deprecations page lists this notice under 'Transcription models'. It is the date OpenAI sent the notice, before the removal date of February 26, 2027. The page's table names gpt-live-transcribe or gpt-transcribe as the replacement for each of the four models.
What it does not show: The notice date is the date OpenAI gives on its own page. The quote also carries the removal date, which is its own fact. The notice is a planned removal, not the removal itself.

A row of History of Dictation Software: A Dated Timeline, as OpenAI transcription notice: 2,026 year.