Data points: 139
Model compare
The readout for GPT-5 and GPT-5.5, before the detailed comparison sheet.
Weighted outcome: GPT-5.5. Benchmark capability categories carry 80%, while price, API performance, and availability carry 20%.
Decision read
GPT-5.5
GPT-5.5 has the higher weighted result; Model A / B score 38.9 to 61.1.
Evidence depth
139 data points
Includes 34 benchmark rows, 1 audit samples, and 6 provider examples.
Selection signal
Start with GPT-5.5
The charts below split 41 high-signal samples across speed, scores, and audit health.
Switch either side of this report to compare another model with the same LMSpeed data pipeline.
Select a different model to open a new comparison URL.
This report only uses LMSpeed data for GPT-5 and GPT-5.5: pricing, speed aggregates, third-party benchmark scores, and shared provider samples.
| Model compare | GPT-5 | GPT-5.5 |
|---|---|---|
| Overall leader | Contender | Leading |
| Weighted overall score | 38.9 pts | 61.1 pts |
| Benchmark category leads | 2 categories | 5 categories |
| Operational advantages | Average speed, First-token latency, Free providers, Provider coverage | Cheapest input price |
| Context window | 400K tokens | 1.1M tokens |
| Max output | 128K tokens | 128K tokens |
| Modalities | Input TextImageFile Output Text |
The overall result weights benchmark capability categories at 80% and price, API speed/latency, and availability at 20%. Recent test volume does not affect the winner, and missing benchmark categories are excluded.
| Model compare | GPT-5 | GPT-5.5 |
|---|---|---|
| Developer | OpenAI | OpenAI |
| Released | Aug 2025 | Apr 2026 |
| Parameters | No data | No data |
| Tokenizer | GPT | GPT |
| Knowledge cutoff | 2024-09-30 | 2025-12-01 |
| OpenRouter ID | openai/gpt-5 | openai/gpt-5.5 |
| References | No data | No data |
This report only uses LMSpeed data for GPT-5 and GPT-5.5: pricing, speed aggregates, third-party benchmark scores, and shared provider samples.
GPT-5
GPT-5 is stronger in benchmark categories (Math, Multimodal) and operational dimensions (Average speed, First-token latency, Free providers, Provider coverage).
GPT-5.5
GPT-5.5 is stronger in benchmark categories (Agents, Coding, Reasoning, Knowledge, Instruction following) and operational dimensions (Cheapest input price).
Third-party benchmark profile synced into LMSpeed; only metrics available for both models are shown.
Compare benchmark category scores on a 0-100 scale. Select a category to inspect the gap.
Avg. score
GPT-5
55.1
Avg. score
GPT-5.5
59.5
GPT-5.5 leads by 16.9
GPT-5.5 leads by 10.0
GPT-5.5 leads by 9.5
GPT-5.5 leads by 7.9
GPT-5 leads by 4.6
GPT-5
GPT-5 leads by 7.7
GPT-5.5 leads by 2.1
Metric-level scores with benchmark source, rank depth, confidence, error, and evaluation date where available.
GPT-5
71.0
Rank #31/127 · confidence 1 · eval date 2025-08-07
GPT-5.5
winner78.0
Rank #17/127 · confidence 3 · eval date 2026-04-23
GPT-5
winner0.91 s
Rank #30/139 · confidence 4
GPT-5.5
62.71 s
Rank #126/139 · confidence 4
GPT-5
winner0.91 s
Rank #48/139 · confidence 4
GPT-5.5
62.71 s
Rank #131/139 · confidence 4
GPT-5
76.6 tok/s
Rank #85/139 · confidence 4
GPT-5.5
winner78.6 tok/s
Rank #81/139 · confidence 4
GPT-5
winner$1.25/M
Rank #109/163 · confidence 4
GPT-5.5
$5.00/M
Rank #147/163 · confidence 4
GPT-5
winner$3.44/M
Rank #119/163 · confidence 4
GPT-5.5
$11.25/M
Rank #152/163 · confidence 4
GPT-5
winner$10.00/M
Rank #122/163 · confidence 4
GPT-5.5
$30.00/M
Rank #152/163 · confidence 4
GPT-5
winner75.6
Rank #2/89 · confidence 1 · eval date 2025-08-07
GPT-5.5
74.3
Rank #4/89 · confidence 3 · eval date 2026-04-23
GPT-5
67.3%
Rank #120/187 · confidence 4
GPT-5.5
winner93.5%
Rank #3/187 · confidence 4
GPT-5
5.7
Rank #30/73 · confidence 1 · eval date 2025-08-07
GPT-5.5
winner27.1
Rank #6/73 · confidence 3 · eval date 2026-04-23
GPT-5
5.4%
Rank #131/186 · confidence 4
GPT-5.5
winner44.3%
Rank #7/186 · confidence 4
GPT-5
71.4
Rank #18/70 · confidence 1 · eval date 2025-08-07
GPT-5.5
winner81.9
Rank #9/70 · confidence 3 · eval date 2026-04-23
GPT-5
20.1
Rank #22/33 · confidence 1 · eval date 2025-08-07
GPT-5.5
winner69.8
Rank #2/33 · confidence 3 · eval date 2026-04-23
GPT-5
32.6
Rank #48/85 · confidence 1 · eval date 2025-08-07
GPT-5.5
winner60.6
Rank #3/85 · confidence 3 · eval date 2026-04-23
GPT-5
37.8
Rank #41/58 · confidence 1 · eval date 2025-08-07
GPT-5.5
winner74.9
Rank #4/58 · confidence 3 · eval date 2026-04-23
GPT-5
42.9
Rank #46/96 · confidence 1 · eval date 2025-08-07
GPT-5.5
winner56.1
Rank #4/96 · confidence 3 · eval date 2026-04-23
GPT-5
38.8%
Rank #82/184 · confidence 4
GPT-5.5
winner56.1%
Rank #4/184 · confidence 4
GPT-5
59.8
Rank #58/100 · confidence 1 · eval date 2025-08-07
GPT-5.5
winner69.7
Rank #41/100 · confidence 3 · eval date 2026-04-23
GPT-5
85.4
Rank #45/96 · confidence 1 · eval date 2025-08-07
GPT-5.5
winner93.5
Rank #3/96 · confidence 3 · eval date 2026-04-23
GPT-5
40.7
Rank #20/90 · confidence 1 · eval date 2025-08-07
GPT-5.5
winner56.9
Rank #3/90 · confidence 3 · eval date 2026-04-23
GPT-5
26.5
Rank #39/96 · confidence 1 · eval date 2025-08-07
GPT-5.5
winner44.3
Rank #5/96 · confidence 3 · eval date 2026-04-23
GPT-5
34.7
Rank #48/99 · confidence 1 · eval date 2025-08-07
GPT-5.5
winner54.8
Rank #5/99 · confidence 3 · eval date 2026-04-23
GPT-5
75.2
Rank #24/92 · confidence 1 · eval date 2025-08-07
GPT-5.5
winner82.2
Rank #15/92 · confidence 3 · eval date 2026-04-23
GPT-5
82.1
Rank #32/90 · confidence 1 · eval date 2025-08-07
GPT-5.5
winner85.5
Rank #25/90 · confidence 3 · eval date 2026-04-23
GPT-5
winner89.3
Rank #4/81 · confidence 1 · eval date 2025-08-07
GPT-5.5
58.4
Rank #54/81 · confidence 3 · eval date 2026-04-23
GPT-5
74.2
Rank #32/57 · confidence 1 · eval date 2025-08-07
GPT-5.5
winner79.9
Rank #8/57 · confidence 3 · eval date 2026-04-23
GPT-5
1219.0
Rank #38/65 · confidence 1 · eval date 2025-08-07
GPT-5.5
winner1287.0
Rank #19/65 · confidence 3 · eval date 2026-04-23
GPT-5
73.1
Rank #29/86 · confidence 1 · eval date 2025-08-07
GPT-5.5
winner75.9
Rank #16/86 · confidence 3 · eval date 2026-04-23
GPT-5
72.9
Rank #27/95 · confidence 1 · eval date 2025-08-07
GPT-5.5
winner96.0
Rank #2/95 · confidence 3 · eval date 2026-04-23
GPT-5
8.5
Rank #19/19 · confidence 1 · eval date 2025-08-07
GPT-5.5
winner42.7
Rank #2/19 · confidence 3 · eval date 2026-04-23
GPT-5
25.7
Rank #28/54 · confidence 1 · eval date 2025-08-07
GPT-5.5
winner44.9
Rank #8/54 · confidence 3 · eval date 2026-04-23
GPT-5
84.8
Rank #47/84 · confidence 1 · eval date 2025-08-07
GPT-5.5
winner98.0
Rank #8/84 · confidence 3 · eval date 2026-04-23
GPT-5
28.7
Rank #31/50 · confidence 1 · eval date 2025-08-07
GPT-5.5
winner49.7
Rank #10/50 · confidence 3 · eval date 2026-04-23
GPT-5
1075.0
Rank #31/54 · confidence 1 · eval date 2025-08-07
GPT-5.5
winner1494.0
Rank #10/54 · confidence 3 · eval date 2026-04-23
Latest completed audits from shared providers, with four safety and integrity score groups plus report links.
| Provider | GPT-5 | GPT-5.5 |
|---|---|---|
Winner: GPT-5.5 | GPT-5 gpt-5 No audit yet | GPT-5.5 gpt-5.5 Audit score 87 768486100 |
Speed aggregates and input/output pricing share each provider row for real API selection and migration cost checks.
| Provider | GPT-5 | GPT-5.5 |
|---|---|---|
35 tests | GPT-5 speed / latency N/A / N/A input / output No data | GPT-5.5 speed / latency 38 tok/s / 8937ms input / output No data |
5 tests | GPT-5 speed / latency 46 tok/s / 6577ms input / output No data | GPT-5.5 speed / latency N/A / N/A input / output No data |
5 tests | GPT-5 speed / latency 102 tok/s / 948ms input / output No data | GPT-5.5 speed / latency N/A / N/A input / output No data |
5 tests | GPT-5 speed / latency 131 tok/s / 743ms input / output No data | GPT-5.5 speed / latency N/A / N/A input / output No data |
5 tests | GPT-5 speed / latency N/A / N/A input / output No data | GPT-5.5 speed / latency 61 tok/s / 5312ms input / output No data |
GPT-5 gpt-5-all speed / latency No data input / output $0/request | GPT-5.5 gpt-5.5 speed / latency No data input / output $0/request |
Weighted outcome: GPT-5.5. Benchmark capability categories carry 80%, while price, API performance, and availability carry 20%.
Input
Output
| Features | Text inputImage inputFile inputText outputTool callingStructured outputsJSON modeReasoning | Text inputImage inputFile inputText outputTool callingStructured outputsJSON modeReasoning |
|---|
