Data points: 81
The readout for GPT-5 and GPT-5.3 Codex, before the detailed comparison sheet.
Decision read
GPT-5.3 Codex
GPT-5.3 Codex currently has the stronger profile, with verified wins split 1 to 4.
Evidence depth
81 data points
Includes 8 benchmark rows, 0 audit samples, and 9 provider examples.
Selection signal
Start with GPT-5.3 Codex
The charts below split 17 high-signal samples across speed, scores, and audit health.
Model compare GPT-5 vs GPT-5.3 Codexgpt-5-vs-gpt-5-3-codex | Model A GPT-5 | Model B GPT-5.3 Codex |
|---|---|---|
| Overall leader | Contender | Leading |
| Verified metric wins | 1 wins | 4 wins |
| Where it leads | Average speed | Cheapest input price, First-token latency, Provider coverage, Recent tests |
Third-party benchmark profile synced into LMSpeed; only metrics available for both models are shown.
| Metric | GPT-5 | GPT-5.3 Codex |
|---|---|---|
| GPQA | 85.4%#31 |
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 |
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.
| Guidance | GPT-5 | GPT-5.3 Codex |
|---|---|---|
| When to choose each model | GPT-5 GPT-5 is stronger when you prioritize Average speed. | GPT-5.3 Codex GPT-5.3 Codex is stronger when you prioritize Cheapest input price, First-token latency, Provider coverage, Recent tests. |
TL;DR: GPT-5.3 Codex leads across 81 verifiable data points, including pricing, speed, latency, benchmarks, and provider examples.
Continue from GPT-5 vs GPT-5.3 Codex into nearby model comparisons with enough verified LMSpeed data.
| Model metadata | GPT-5 exposes 128K tokens; notable signals: Text input, Image input, File input, Text output. | GPT-5.3 Codex exposes 400K tokens; notable signals: Text input, Image input, File input, Text output. |
|---|---|---|
| Developer | OpenAI | OpenAI |
| Context window | 128K tokens | 400K tokens |
| Max output | 16.4K tokens | 128K tokens |
| Released | Aug 2025 | Feb 2026 |
| Modalities | Input FileImageText Output Text | Input TextImageFile Output Text |
| Features | Text inputImage inputFile inputText outputStructured outputsJSON mode | Text inputImage inputFile inputText outputTool callingStructured outputsJSON modeReasoning |
| Parameters | No data | No data |
| Tokenizer | GPT | GPT |
| Knowledge cutoff | 2024-09-30 | No data |
| OpenRouter ID | openai/gpt-5-chat | openai/gpt-5.3-codex |
| References | No data | No data |
| HLE | 26.5%#24 | 39.9%#5 |
|---|
| SciCode | 42.9%#31 | 53.2%#8 |
|---|
| Input price | $1.25/M#30 | $1.75/M#35 |
|---|
| Output price | $10.00/M#41 | $14.00/M#43 |
|---|
| Output speed | 109.6 tok/s#44 | 77.7 tok/s#66 |
|---|
| Blended price | $3.44/M#58 | $4.81/M#62 |
|---|
| Time to first answer token | 62.85 s#98 | 57.06 s#95 |
|---|
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 speed / latency No data input / output $0/M / $0/M | GPT-5.3 Codex gpt-5.3-codex-openai-compact speed / latency No data input / output $75.00/M / $600.00/M |
GPT-5 gpt-5-high speed / latency No data input / output $0.0068/M / $0.0068/M | GPT-5.3 Codex gpt-5.3-codex-xhigh 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/M / $0.0068/M | 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/M / $0.0068/M | GPT-5.3 Codex gpt-5.3-codex-medium speed / latency No data input / output $0.240/M / $1.92/M |
Rankings are based on community-submitted tests and periodic health probes. Advisory only, not official data.
