OpenAI
GPT-5.5
Announced Apr 23, 2026
Carry a larger task through to completion
What could it do?
OpenAI reported gains in coding, research, data analysis and computer use.
What changed?
Improved task persistence and efficiency over GPT-5.4.
Made longer workflows and early scientific research more practical.
Where it fell short
The initial app rollout preceded API availability on April 24.
Release facts were checked against the sources below. Performance claims belong to the developers; we have not independently tested these models.
Developer announcement or release logBenchmark results
A benchmark estimate, not a percentage or capability multiplier. Reasoning settings are not specified in this source table. Historical estimates can change in later snapshots.
Epoch AI methodology ↗Download the source snapshotChecked Oct 7, 2026 · CC BY 4.0One explicitly named variant per release. Scores come from the same Overall snapshot; preliminary entries and reported intervals are preserved. These are current ratings of earlier variants, not their launch day ratings.
Source: Text Arena ↗Download selected resultsChecked Oct 8, 2026