GPT 5.4 (xhigh)

GPT 5.4 (xhigh) is a model from OpenAI, released March 5, 2026. Its best result is #17 of 151 on LegalBench.

Release Date: Mar 5, 2026

Developer OpenAI  🇺🇸
Context Window 1M
Max Output Tokens 128k
Token Costs (in/out) $2.50/15.00
Weights Private
Input Modalities

Accuracy

64.50 %

Avg. Cost (In/Out)

$ 2.50 / $ 15.00

Latency

13 min 24 s

Vals Index
BenchmarksAccuracyRankings

34.98%

±4.11
37/79

41.29%

±2.15
55/107

77.55%

±3.32
69/109

68.32%

±0.92
17/98

43.31%

±3.12
50/91

73.96%

±0.87
44/145

67.42%

±4.84
46/118

91.67%

±1.91
21/138

84.14%

±1.04
41/143

86.04%

±0.41
17/151

87.48%

±0.42
27/138

87.51%

±0.80
15/93

0.00%

±0.00
40/64

51.71%

±4.72
19/35

78.20%

±1.85
30/88

58.43%

±5.25
12/67
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

Mar 5, 2026

We evaluated GPT 5.4 (xhigh) across our full benchmark suite.

Evaluations were run via the official OpenAI API using “xhigh” reasoning, except on Terminal-Bench 2.0, where we used “high”.