GPT 5.5

Release Date: Apr 23, 2026

Developer OpenAIΒ πŸ‡ΊπŸ‡Έ
Context Window 1M
Max Output Tokens 128k
Token Costs (in/out) $5.00/30.00
Weights Private
Input Modalities

Accuracy

57.41 % Β± 1.15

Cost / Test (Vals Index)

$ 6.142

Latency

20 min 51 s

Vals Index
BenchmarksAccuracyRankings

0.0%

Β±1.15
17/57

0.0%

Β±4.16
10/59

0.0%

Β±5.16
3/25

0.0%

Β±2.87
15/57

0.0%

Β±0.55
23/60

0.0%

Β±0.00
8/11

0.0%

Β±3.41
18/60

0.0%

Β±2.19
20/92

0.0%

Β±1.93
13/94

0.0%

Β±0.91
10/98

0.0%

Β±3.95
11/81

0.0%

Β±1.19
6/9

0.0%

Β±3.22
15/20

0.0%

Β±0.85
25/145

0.0%

Β±4.54
24/95

0.0%

Β±1.29
11/138

0.0%

Β±1.02
35/143

0.0%

Β±0.41
11/144

0.0%

Β±0.32
21/138

0.0%

Β±0.77
9/93

0.0%

Β±0.50
11/45

0.0%

Β±4.52
5/35

0.0%

Β±1.70
19/88

0.0%

Β±0.65
13/65
Proprietary BenchmarksAcademic BenchmarksIndustry Partners
Vals
Default Provider : OpenAI
Temperature: Default
Top P: Default
Top K: Default
Max Output Tokens: 128,000
Reasoning Effort: xhigh

Updates

Apr 23, 2026

OpenAI released GPT 5.5, and it lands near the top of multiple Vals leaderboards, taking #2 on the overall Vals Index with a meaningful jump over GPT 5.4 (xhigh) in roughly six weeks.