Data points: 105
Model compare
The readout for GPT-5 and GPT-5.3 Codex, before the detailed comparison sheet.
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 12 to 88.
Evidence depth
105 data points
Includes 20 benchmark rows, 0 audit samples, and 6 provider examples.
Selection signal
Start with GPT-5.3 Codex
The charts below split 26 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-5.3 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 | 12.0 pts | 88.0 pts |
| Benchmark category leads | 0 categories | 5 categories |
| Operational advantages | Cheapest input price, Average speed, Free providers | First-token latency, Provider coverage |
| Context window | 400K tokens | 400K tokens |
| Max output | 128K tokens | 128K tokens |
| Modalities | Input TextImageFile Output Text | Input |
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-5.3 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 |
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, Free providers.
GPT-5.3 Codex
GPT-5.3 Codex is stronger in benchmark categories (Agents, Coding, Reasoning, Knowledge, Instruction following) and operational dimensions (First-token latency, Provider coverage).
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
51.9
Avg. score
GPT-5.3 Codex
56.5
GPT-5.3 Codex leads by 7.6
GPT-5.3 Codex leads by 9.8
GPT-5.3 Codex leads by 8.6
GPT-5.3 Codex leads by 5.1
GPT-5
No data
No data
GPT-5.3 Codex leads by 1.8
Metric-level scores with benchmark source, rank depth, confidence, error, and evaluation date where available.
GPT-5
winner$1.25/M
Rank #107/162 · confidence 4
GPT-5.3 Codex
$1.75/M
Rank #120/162 · confidence 4
GPT-5
winner$3.44/M
Rank #117/162 · confidence 4
GPT-5.3 Codex
$4.81/M
Rank #132/162 · confidence 4
GPT-5
winner$10.00/M
Rank #120/162 · confidence 4
GPT-5.3 Codex
$14.00/M
Rank #133/162 · confidence 4
GPT-5
winner75.6
Rank #2/89 · confidence 1 · eval date 2025-08-07
GPT-5.3 Codex
74.0
Rank #6/89 · confidence 1 · eval date 2026-02-05
GPT-5
67.3%
Rank #121/188 · confidence 4
GPT-5.3 Codex
winner91.5%
Rank #12/188 · confidence 4
GPT-5
5.7
Rank #30/73 · confidence 1 · eval date 2025-08-07
GPT-5.3 Codex
winner16.9
Rank #13/73 · confidence 1 · eval date 2026-02-05
GPT-5
5.4%
Rank #132/187 · confidence 4
GPT-5.3 Codex
winner39.9%
Rank #13/187 · 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 1 · eval date 2026-02-05
GPT-5
38.8%
Rank #83/185 · confidence 4
GPT-5.3 Codex
winner53.2%
Rank #11/185 · confidence 4
GPT-5
42.9
Rank #46/96 · confidence 1 · eval date 2025-08-07
GPT-5.3 Codex
winner53.2
Rank #15/96 · confidence 1 · eval date 2026-02-05
GPT-5
40.7
Rank #20/90 · confidence 1 · eval date 2025-08-07
GPT-5.3 Codex
winner51.8
Rank #8/90 · confidence 1 · eval date 2026-02-05
GPT-5
26.5
Rank #39/96 · confidence 1 · eval date 2025-08-07
GPT-5.3 Codex
winner39.9
Rank #12/96 · confidence 1 · eval date 2026-02-05
GPT-5
85.4
Rank #45/96 · confidence 1 · eval date 2025-08-07
GPT-5.3 Codex
winner91.5
Rank #13/96 · confidence 1 · eval date 2026-02-05
GPT-5
34.7
Rank #48/99 · confidence 1 · eval date 2025-08-07
GPT-5.3 Codex
winner44.3
Rank #17/99 · confidence 1 · eval date 2026-02-05
GPT-5
82.1
Rank #31/90 · confidence 1 · eval date 2025-08-07
GPT-5.3 Codex
winner86.9
Rank #22/90 · confidence 1 · eval date 2026-02-05
GPT-5
74.2
Rank #32/57 · confidence 1 · eval date 2025-08-07
GPT-5.3 Codex
winner78.5
Rank #15/57 · confidence 1 · eval date 2026-02-05
GPT-5
winner1214.0
Rank #40/66 · confidence 1 · eval date 2025-08-07
GPT-5.3 Codex
1193.0
Rank #46/66 · confidence 1 · eval date 2026-02-05
GPT-5
73.1
Rank #29/86 · confidence 1 · eval date 2025-08-07
GPT-5.3 Codex
winner75.4
Rank #21/86 · confidence 1 · eval date 2026-02-05
GPT-5
8.5
Rank #20/20 · confidence 1 · eval date 2025-08-07
GPT-5.3 Codex
winner33.7
Rank #8/20 · confidence 1 · eval date 2026-02-05
GPT-5
84.8
Rank #44/84 · confidence 1 · eval date 2025-08-07
GPT-5.3 Codex
winner86.0
Rank #41/84 · confidence 1 · eval date 2026-02-05
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. | ||
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 |
|---|---|---|
40 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 |
20 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 |
14 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 |
10 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 |
10 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-chat-latest speed / latency No data input / output $0/request | GPT-5.3 Codex gpt-5.3-codex speed / latency No data input / output $0/request |
Weighted outcome: GPT-5.3 Codex. Benchmark capability categories carry 80%, while price, API performance, and availability carry 20%.
Output
| Features | Text inputImage inputFile inputText outputTool callingStructured outputsJSON modeReasoning | Text inputImage inputFile inputText outputTool callingStructured outputsJSON modeReasoning |
|---|
