Data points: 62
Model compare
The readout for GPT-5.3 Codex and O3 Deep Research, 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 100 to 0.
Evidence depth
62 data points
Includes 0 benchmark rows, 0 audit samples, and 6 provider examples.
Selection signal
Start with GPT-5.3 Codex
The charts below split 6 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-5.3 Codex and O3 Deep Research: pricing, speed aggregates, third-party benchmark scores, and shared provider samples.
| Model compare | GPT-5.3 Codex | O3 Deep Research |
|---|---|---|
| Overall leader | Leading | Contender |
| Weighted overall score | 100.0 pts | 0.0 pts |
| Benchmark category leads | 0 categories | 0 categories |
| Operational advantages | Cheapest input price, Free providers, Provider coverage | No data |
| Context window | 400K tokens | 200K tokens |
| Max output | 128K tokens | 100K 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-5.3 Codex | O3 Deep Research |
|---|---|---|
| Developer | OpenAI | OpenAI |
| Released | Feb 2026 | Oct 2025 |
| Parameters | No data | No data |
| Tokenizer | GPT | GPT |
| Knowledge cutoff | No data | No data |
| OpenRouter ID | openai/gpt-5.3-codex | openai/o3-deep-research |
| References | No data | No data |
This report only uses LMSpeed data for GPT-5.3 Codex and O3 Deep Research: pricing, speed aggregates, third-party benchmark scores, and shared provider samples.
GPT-5.3 Codex
GPT-5.3 Codex has these operational advantages: Cheapest input price, Free providers, Provider coverage.
O3 Deep Research
O3 Deep Research does not clearly lead in the benchmark or operational dimensions shared by both models.
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-5.3 Codex
56.7
Avg. score
O3 Deep Research
-
GPT-5.3 Codex
GPT-5.3 Codex
GPT-5.3 Codex
GPT-5.3 Codex
No data
No data
No data
GPT-5.3 Codex
Metric-level scores with benchmark source, rank depth, confidence, error, and evaluation date where available.
No shared professional benchmark scores are available yet.
Latest completed audits from shared providers, with four safety and integrity score groups plus report links.
| Provider | GPT-5.3 Codex | O3 Deep Research |
|---|---|---|
| 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-5.3 Codex | O3 Deep Research |
|---|---|---|
5 tests | GPT-5.3 Codex speed / latency 21 tok/s / 2445ms input / output No data | O3 Deep Research speed / latency N/A / N/A input / output No data |
5 tests | GPT-5.3 Codex speed / latency 45 tok/s / 6276ms input / output No data | O3 Deep Research speed / latency N/A / N/A input / output No data |
5 tests | GPT-5.3 Codex speed / latency 53 tok/s / 3889ms input / output No data | O3 Deep Research speed / latency N/A / N/A input / output No data |
0 tests | GPT-5.3 Codex speed / latency N/A / N/A input / output No data | O3 Deep Research speed / latency N/A / N/A input / output No data |
0 tests | GPT-5.3 Codex speed / latency N/A / N/A input / output No data | O3 Deep Research speed / latency N/A / N/A input / output No data |
GPT-5.3 Codex gpt-5.3-codex speed / latency No data input / output $0/request | O3 Deep Research o3-deep-research 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%.
Input
Output
| Features | Text inputImage inputFile inputText outputTool callingStructured outputsJSON modeReasoning | Text inputImage inputFile inputText outputTool callingStructured outputsJSON modeReasoning |
|---|
