Outage in OpenAI ChatGPT
Some users may encounter issues with GPT-5.4-C model in Codex
Resolved Minor
April 21, 2026 - Started about 18 hours ago
- Lasted about 2 hours
Incident Report
Summary AI Generated
OpenAI experienced issues with the GPT-5.4-C model in Codex that affected some users for 2 hours. The incident impacted both Codex and ChatGPT services. A mitigation was applied and the service was being monitored for recovery.
We have applied the mitigation and are monitoring the recovery.
Components affected
OpenAI ChatGPT Codex OpenAI ChatGPT ChatGPTLatest Updates ( sorted recent to last )
MONITORING
about 18 hours ago - at 04/21/2026 02:34AM
We have applied the mitigation and are monitoring the recovery.
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