Data points: 115
The readout for GPT-5.3 Codex and O3 Mini, before the detailed comparison sheet.
Decision read
GPT-5.3 Codex
GPT-5.3 Codex currently has the stronger profile, with verified wins split 6 to 0.
Evidence depth
115 data points
Includes 25 benchmark rows, 0 audit samples, and 7 provider examples.
Selection signal
Start with GPT-5.3 Codex
The charts below split 32 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.
Model compare GPT-5.3 Codex vs O3 Minigpt-5-3-codex-vs-o3-mini | Model A GPT-5.3 Codex | Model B O3 Mini |
|---|---|---|
| Overall leader | Leading | Contender |
| Verified metric wins | 6 wins | 0 wins |
| Where it leads | Cheapest input price, Average speed, First-token latency, Free providers, Provider coverage, Recent tests |
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
67.1
Avg. score
O3 Mini
59.2
Selected category
Agents
GPT-5.3 Codex leads by 40.5
Metric-level scores with benchmark source, rank depth, confidence, error, and evaluation date where available.
GPT-5.3 Codex
winner85.0
Rank #8/82 · confidence 1 · eval date 2026-02-05
O3 Mini
55.0
Rank #43/82 · confidence 1 · eval date 2025-01-31
GPT-5.3 Codex
83.6 tok/s
Rank #38/78 · confidence 4
O3 Mini
winner224.5 tok/s
Rank #4/78 · confidence 4
GPT-5.3 Codex
67.20 s
Rank #71/78 · confidence 4
O3 Mini
winner15.30 s
Rank #48/78 · confidence 4
GPT-5.3 Codex
67.20 s
Rank #74/78 · confidence 4
O3 Mini
winner15.30 s
Rank #65/78 · confidence 4
GPT-5.3 Codex
$14.00/M
Rank #75/95 · confidence 4
O3 Mini
winner$4.40/M
Rank #56/95 · confidence 4
GPT-5.3 Codex
$4.81/M
Rank #75/95 · confidence 4
O3 Mini
winner$1.93/M
Rank #57/95 · confidence 4
GPT-5.3 Codex
$1.75/M
Rank #69/95 · confidence 4
O3 Mini
winner$1.10/M
Rank #58/95 · confidence 4
GPT-5.3 Codex
winner93.0
Rank #4/57 · confidence 1 · eval date 2026-02-05
O3 Mini
68.0
Rank #19/57 · confidence 1 · eval date 2025-01-31
GPT-5.3 Codex
winner91.5%
Rank #6/103 · confidence 4
O3 Mini
77.3%
Rank #54/103 · confidence 4
GPT-5.3 Codex
winner39.9%
Rank #8/103 · confidence 4
O3 Mini
12.3%
Rank #52/103 · confidence 4
GPT-5.3 Codex
winner85.0
Rank #4/28 · confidence 1 · eval date 2026-02-05
O3 Mini
49.3
Rank #26/28 · confidence 1 · eval date 2025-01-31
GPT-5.3 Codex
winner53.1
Rank #5/61 · confidence 1 · eval date 2026-02-05
O3 Mini
17.9
Rank #54/61 · confidence 1 · eval date 2025-01-31
GPT-5.3 Codex
winner53.0
Rank #5/59 · confidence 1 · eval date 2026-02-05
O3 Mini
6.8
Rank #54/59 · confidence 1 · eval date 2025-01-31
GPT-5.3 Codex
winner53.2
Rank #7/63 · confidence 1 · eval date 2026-02-05
O3 Mini
39.9
Rank #39/63 · confidence 1 · eval date 2025-01-31
GPT-5.3 Codex
winner53.2%
Rank #8/101 · confidence 4
O3 Mini
39.8%
Rank #49/101 · confidence 4
GPT-5.3 Codex
winner86.7
Rank #10/69 · confidence 1 · eval date 2026-02-05
O3 Mini
48.5
Rank #45/69 · confidence 1 · eval date 2025-01-31
GPT-5.3 Codex
winner91.5
Rank #4/63 · confidence 1 · eval date 2026-02-05
O3 Mini
74.8
Rank #44/63 · confidence 1 · eval date 2025-01-31
GPT-5.3 Codex
winner39.9
Rank #5/63 · confidence 1 · eval date 2026-02-05
O3 Mini
8.7
Rank #42/63 · confidence 1 · eval date 2025-01-31
GPT-5.3 Codex
winner44.3
Rank #6/66 · confidence 1 · eval date 2026-02-05
O3 Mini
19.0
Rank #51/66 · confidence 1 · eval date 2025-01-31
GPT-5.3 Codex
winner91.2
Rank #7/67 · confidence 1 · eval date 2026-02-05
O3 Mini
60.7
Rank #36/67 · confidence 1 · eval date 2025-01-31
GPT-5.3 Codex
winner96.9
Rank #5/50 · confidence 1 · eval date 2026-02-05
O3 Mini
44.8
Rank #35/50 · confidence 1 · eval date 2025-01-31
GPT-5.3 Codex
winner95.8
Rank #3/60 · confidence 1 · eval date 2026-02-05
O3 Mini
65.6
Rank #26/60 · confidence 1 · eval date 2025-01-31
GPT-5.3 Codex
winner91.4
Rank #11/56 · confidence 1 · eval date 2026-02-05
O3 Mini
85.3
Rank #13/56 · confidence 1 · eval date 2025-01-31
GPT-5.3 Codex
winner76.9
Rank #12/69 · confidence 1 · eval date 2026-02-05
O3 Mini
60.6
Rank #24/69 · confidence 1 · eval date 2025-01-31
GPT-5.3 Codex
winner86.0
Rank #21/58 · confidence 1 · eval date 2026-02-05
O3 Mini
28.7
Rank #51/58 · confidence 1 · eval date 2025-01-31
Latest completed audits from shared providers, with four safety and integrity score groups plus report links.
| Provider | GPT-5.3 Codex | O3 Mini |
|---|---|---|
| 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 Mini |
|---|---|---|
10 tests | GPT-5.3 Codex speed / latency 57 tok/s / 2985ms input / output No data |
This report only uses LMSpeed data for GPT-5.3 Codex and O3 Mini: pricing, speed aggregates, third-party benchmark scores, and shared provider samples.
| Guidance | GPT-5.3 Codex | O3 Mini |
|---|---|---|
| When to choose each model | GPT-5.3 Codex GPT-5.3 Codex is stronger when you prioritize Cheapest input price, Average speed, First-token latency, Free providers, Provider coverage, Recent tests. | O3 Mini O3 Mini does not clearly lead on the verified metrics here, so check provider-specific pricing before choosing. |
TL;DR: GPT-5.3 Codex leads across 115 verifiable data points, including pricing, speed, latency, benchmarks, and provider examples.
Continue from GPT-5.3 Codex vs O3 Mini into nearby model comparisons with enough verified LMSpeed data.
| No data |
| Model metadata | GPT-5.3 Codex exposes 400K tokens; notable signals: Text input, Image input, File input, Text output. | O3 Mini exposes 200K tokens; notable signals: Text input, File input, Text output, Tool calling. |
|---|---|---|
| Developer | OpenAI | OpenAI |
| Context window | 400K tokens | 200K tokens |
| Max output | 128K tokens | 100K tokens |
| Released | Feb 2026 | Feb 2025 |
| Modalities | Input TextImageFile Output Text | Input TextFile Output Text |
| Features | Text inputImage inputFile inputText outputTool callingStructured outputsJSON modeReasoning | Text inputFile inputText outputTool callingStructured outputsJSON modeReasoning |
| Parameters | No data | No data |
| Tokenizer | GPT | GPT |
| Knowledge cutoff | No data | 2023-10-31 |
| OpenRouter ID | openai/gpt-5.3-codex | openai/o3-mini-high |
| References | No data | No data |
O3 Mini
speed / latency
N/A / N/A
input / output
No data
ZetaTechs API6 tests | GPT-5.3 Codex speed / latency N/A / N/A input / output No data | O3 Mini speed / latency 44 tok/s / 17418ms input / output No data |
|---|
DuckCoding5 tests | GPT-5.3 Codex speed / latency 21 tok/s / 2445ms input / output No data | O3 Mini speed / latency N/A / N/A input / output No data |
|---|
N1N5 tests | GPT-5.3 Codex speed / latency N/A / N/A input / output No data | O3 Mini speed / latency 117 tok/s / 4809ms input / output No data |
|---|
Seamee API5 tests | GPT-5.3 Codex speed / latency 53 tok/s / 3889ms input / output No data | O3 Mini speed / latency N/A / N/A input / output No data |
|---|
GPT-5.3 Codex gpt-5.3-codex-medium speed / latency No data input / output $0.014/M / $0.014/M | O3 Mini o3-mini-high-all speed / latency No data input / output $10.27/M / $41.10/M |
GPT-5.3 Codex gpt-5.3-codex speed / latency No data input / output $0.024/M / $0.192/M | O3 Mini o3-mini-high speed / latency No data input / output $0.021/M / $0.082/M |
Rankings are based on community-submitted tests and periodic health probes. Advisory only, not official data.
