Data points: 111
Model compare
GPT-5 vs GPT-5.3 Codex
The readout for GPT-5 and GPT-5.3 Codex, before the detailed comparison sheet.
Key Takeaways
Weighted outcome: GPT-5.3 Codex. Benchmark capability categories carry 80%, while price, API performance, and availability carry 20%.
Decision read
GPT-5.3 Codex
GPT-5.3 Codex has the higher weighted result; Model A / B score 8 to 92.
Evidence depth
111 data points
Includes 23 benchmark rows, 0 audit samples, and 10 provider examples.
Selection signal
Start with GPT-5.3 Codex
The charts below split 33 high-signal samples across speed, scores, and audit health.
Change comparison
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.
Comparison sheet
This report only uses LMSpeed data for GPT-5 and GPT-5.3 Codex: pricing, speed aggregates, third-party benchmark scores, and shared provider samples.
| Model compare | GPT-5 | GPT-5.3 Codex |
|---|---|---|
| Overall leader | Contender | Leading |
| Weighted overall score | 8.0 pts | 92.0 pts |
| Benchmark category leads | 0 categories | 6 categories |
| Operational advantages | Cheapest input price, Average speed | First-token latency, Free providers, Provider coverage |
| Context window | 400K tokens | 400K tokens |
| Max output | 128K tokens | 128K tokens |
| Modalities | Input TextImageFile Output Text | Input TextImageFile Output Text |
| Features | Text inputImage inputFile inputText outputTool callingStructured outputsJSON modeReasoning | Text inputImage inputFile inputText outputTool callingStructured outputsJSON modeReasoning |
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 metadata
Model metadata
| Model compare | GPT-5 | GPT-5.3 Codex |
|---|---|---|
| Developer | OpenAI | OpenAI |
| Released | Aug 2025 | Feb 2026 |
| Parameters | No data | No data |
| Tokenizer | GPT | GPT |
| Knowledge cutoff | 2024-09-30 | No data |
| OpenRouter ID | openai/gpt-5 | openai/gpt-5.3-codex |
| References | No data | No data |
When to choose each model
This report only uses LMSpeed data for GPT-5 and GPT-5.3 Codex: pricing, speed aggregates, third-party benchmark scores, and shared provider samples.
GPT-5
GPT-5 has these operational advantages: Cheapest input price, Average speed.
GPT-5.3 Codex
GPT-5.3 Codex is stronger in benchmark categories (Agents, Coding, Reasoning, Knowledge, Multimodal) and operational dimensions (First-token latency, Free providers, Provider coverage).
Benchmark score comparison
Third-party benchmark profile synced into LMSpeed; only metrics available for both models are shown.
Category performance
Compare benchmark category scores on a 0-100 scale. Select a category to inspect the gap.
- Model A coverage
- 7 / 8
- Model B coverage
- 6 / 8
- Shared
- 6 shared categories
Avg. score
GPT-5
50.9
Avg. score
GPT-5.3 Codex
55.3
Agents
GPT-5.3 Codex leads by 6.3
Coding
GPT-5.3 Codex leads by 8.5
Reasoning
GPT-5.3 Codex leads by 9.1
Knowledge
GPT-5.3 Codex leads by 7.9
Math
GPT-5
Multilingual
No data
Multimodal
GPT-5.3 Codex leads by 2.9
Instruction following
GPT-5.3 Codex leads by 1.8
Professional benchmark details
Metric-level scores with benchmark source, rank depth, confidence, error, and evaluation date where available.
Professional benchmark details
Metric-level scores with benchmark source, rank depth, confidence, error, and evaluation date where available.
GPT-5
67.0
Rank #27/111 · confidence 1 · eval date 2025-08-07
GPT-5.3 Codex
winner68.0
Rank #26/111 · confidence 3 · eval date 2026-02-05
GPT-5
winner$1.25/M
Rank #123/186 · confidence 4
GPT-5.3 Codex
$1.75/M
Rank #140/186 · confidence 4
GPT-5
winner$3.44/M
Rank #139/186 · confidence 4
GPT-5.3 Codex
$4.81/M
Rank #155/186 · confidence 4
GPT-5
winner$10.00/M
Rank #142/186 · confidence 4
GPT-5.3 Codex
$14.00/M
Rank #156/186 · confidence 4
GPT-5
73.2
Rank #31/67 · confidence 1 · eval date 2025-08-07
GPT-5.3 Codex
winner78.3
Rank #5/67 · confidence 3 · eval date 2026-02-05
GPT-5
76.0
Rank #46/106 · confidence 1 · eval date 2025-08-07
GPT-5.3 Codex
winner83.3
Rank #6/106 · confidence 3 · eval date 2026-02-05
GPT-5
67.3%
Rank #148/218 · confidence 4
GPT-5.3 Codex
winner91.5%
Rank #21/218 · confidence 4
GPT-5
6.0%
Rank #158/216 · confidence 4
GPT-5.3 Codex
winner42.5%
Rank #22/216 · confidence 4
GPT-5
20.1
Rank #22/33 · confidence 1 · eval date 2025-08-07
GPT-5.3 Codex
winner61.8
Rank #4/33 · confidence 3 · eval date 2026-02-05
GPT-5
41.1
Rank #66/113 · confidence 2 · eval date 2025-08-07
GPT-5.3 Codex
winner53.2
Rank #26/113 · confidence 3 · eval date 2026-02-05
GPT-5
39.5
Rank #38/106 · confidence 1 · eval date 2025-08-07
GPT-5.3 Codex
winner52.9
Rank #11/106 · confidence 3 · eval date 2026-02-05
GPT-5
65.4
Rank #51/83 · confidence 1 · eval date 2025-08-07
GPT-5.3 Codex
winner79.5
Rank #19/83 · confidence 3 · eval date 2026-02-05
GPT-5
25.4
Rank #60/114 · confidence 1 · eval date 2025-08-07
GPT-5.3 Codex
winner42.5
Rank #21/114 · confidence 3 · eval date 2026-02-05
GPT-5
83.2
Rank #32/106 · confidence 1 · eval date 2025-08-07
GPT-5.3 Codex
winner89.2
Rank #21/106 · confidence 3 · eval date 2026-02-05
GPT-5
84.2
Rank #64/113 · confidence 1 · eval date 2025-08-07
GPT-5.3 Codex
winner91.5
Rank #23/113 · confidence 3 · eval date 2026-02-05
GPT-5
22.9
Rank #76/117 · confidence 1 · eval date 2025-08-07
GPT-5.3 Codex
winner32.5
Rank #43/117 · confidence 3 · eval date 2026-02-05
GPT-5
69.4
Rank #27/56 · confidence 1 · eval date 2025-08-07
GPT-5.3 Codex
winner75.6
Rank #20/56 · confidence 3 · eval date 2026-02-05
GPT-5
74.3
Rank #38/68 · confidence 1 · eval date 2025-08-07
GPT-5.3 Codex
winner78.5
Rank #22/68 · confidence 3 · eval date 2026-02-05
GPT-5
winner1199.0
Rank #52/78 · confidence 1 · eval date 2025-08-07
GPT-5.3 Codex
1177.0
Rank #59/78 · confidence 3 · eval date 2026-02-05
GPT-5
86.3
Rank #27/52 · confidence 1 · eval date 2025-08-07
GPT-5.3 Codex
winner92.6
Rank #10/52 · confidence 3 · eval date 2026-02-05
GPT-5
70.6
Rank #32/84 · confidence 1 · eval date 2025-08-07
GPT-5.3 Codex
winner75.4
Rank #18/84 · confidence 3 · eval date 2026-02-05
GPT-5
8.5
Rank #24/24 · confidence 1 · eval date 2025-08-07
GPT-5.3 Codex
winner33.7
Rank #11/24 · confidence 3 · eval date 2026-02-05
GPT-5
winner86.5
Rank #39/82 · confidence 1 · eval date 2025-08-07
GPT-5.3 Codex
86.0
Rank #42/82 · confidence 3 · eval date 2026-02-05
API audit comparison
Latest completed audits from shared providers, with four safety and integrity score groups plus report links.
API audit comparison
Latest completed audits from shared providers, with four safety and integrity score groups plus report links.
| Provider | GPT-5 | GPT-5.3 Codex |
|---|---|---|
| No completed audits are available from shared providers yet. | ||
Provider examples
Speed aggregates and input/output pricing share each provider row for real API selection and migration cost checks.
Provider examples
Speed aggregates and input/output pricing share each provider row for real API selection and migration cost checks.
| Provider | GPT-5 | GPT-5.3 Codex |
|---|---|---|
星见雅 API40 tests | GPT-5 speed / latency 38 tok/s / 15844ms input / output No data | GPT-5.3 Codex speed / latency 38 tok/s / 4553ms input / output No data |
V-API20 tests | GPT-5 speed / latency 95 tok/s / 1234ms input / output No data | GPT-5.3 Codex speed / latency N/A / N/A input / output No data |
Mars HK14 tests | GPT-5 speed / latency N/A / N/A input / output No data | GPT-5.3 Codex speed / latency 252 tok/s / 2196ms input / output No data |
QQ Code10 tests | GPT-5 speed / latency N/A / N/A input / output No data | GPT-5.3 Codex speed / latency 57 tok/s / 2985ms input / output No data |
小水管 API10 tests | GPT-5 speed / latency N/A / N/A input / output No data | GPT-5.3 Codex speed / latency 201 tok/s / 2135ms input / output No data |
GPT-5 gpt-5-high speed / latency No data input / output $0/request | GPT-5.3 Codex gpt-5.3-codex-xhigh speed / latency No data input / output $0/request | |
GPT-5 gpt-5 speed / latency No data input / output $0.0014/request | GPT-5.3 Codex gpt-5.3-codex-spark speed / latency No data input / output $0.060/M/$0.479/M | |
GPT-5 gpt-5 speed / latency No data input / output $0.0068/request | GPT-5.3 Codex gpt-5.3-codex speed / latency No data input / output $0.0068/request | |
GPT-5 gpt-5-all speed / latency No data input / output $0.0068/request | GPT-5.3 Codex gpt-5.3-codex-medium speed / latency No data input / output $0.240/M/$1.92/M | |
GPT-5 gpt-5-all speed / latency No data input / output $0.0068/request | GPT-5.3 Codex gpt-5.3-codex speed / latency No data input / output $0.240/M/$1.92/M |
FAQ
Weighted outcome: GPT-5.3 Codex. Benchmark capability categories carry 80%, while price, API performance, and availability carry 20%.
- Why is this comparison indexable?
- It has 6 verifiable comparison points, and both models have pricing or benchmark data.
- Are missing metrics invented?
- No. Metrics without LMSpeed data are omitted from this report.