Data points: 74
The readout for GPT-5.3 Codex and Kat Coder Pro V2, before the detailed comparison sheet.
Decision read
GPT-5.3 Codex
GPT-5.3 Codex currently has the stronger profile, with verified wins split 4 to 0.
Evidence depth
74 data points
Includes 6 benchmark rows, 0 audit samples, and 5 provider examples.
Selection signal
Start with GPT-5.3 Codex
The charts below split 11 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 Kat Coder Pro V2gpt-5-3-codex-vs-kat-coder-pro-v2 | Model A GPT-5.3 Codex | Model B Kat Coder Pro V2 |
|---|---|---|
| Overall leader | Leading | Contender |
| Verified metric wins | 4 wins | 0 wins |
| Where it leads | Cheapest input price, 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
66.4
Avg. score
Kat Coder Pro V2
44.6
Selected category
Coding
GPT-5.3 Codex leads by 21.9
Metric-level scores with benchmark source, rank depth, confidence, error, and evaluation date where available.
GPT-5.3 Codex
$4.81/M
Rank #138/167 · confidence 4
Kat Coder Pro V2
winner$0.525/M
Rank #43/167 · confidence 4
GPT-5.3 Codex
$14.00/M
Rank #139/167 · confidence 4
Kat Coder Pro V2
winner$1.20/M
Rank #45/167 · confidence 4
GPT-5.3 Codex
$1.75/M
Rank #126/167 · confidence 4
Kat Coder Pro V2
winner$0.300/M
Rank #47/167 · confidence 4
GPT-5.3 Codex
winner91.5%
Rank #11/187 · confidence 4
Kat Coder Pro V2
85.5%
Rank #41/187 · confidence 4
GPT-5.3 Codex
winner39.9%
Rank #12/186 · confidence 4
Kat Coder Pro V2
16.0%
Rank #66/186 · confidence 4
GPT-5.3 Codex
winner53.2%
Rank #10/184 · confidence 4
Kat Coder Pro V2
38.3%
Rank #87/184 · confidence 4
Latest completed audits from shared providers, with four safety and integrity score groups plus report links.
| Provider | GPT-5.3 Codex | Kat Coder Pro V2 |
|---|---|---|
| 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 | Kat Coder Pro V2 |
|---|---|---|
5 tests | GPT-5.3 Codex speed / latency 35 tok/s / 17640ms input / output No data | Kat Coder Pro V2 |
This report only uses LMSpeed data for GPT-5.3 Codex and Kat Coder Pro V2: pricing, speed aggregates, third-party benchmark scores, and shared provider samples.
| Guidance | GPT-5.3 Codex | Kat Coder Pro V2 |
|---|---|---|
| When to choose each model | GPT-5.3 Codex GPT-5.3 Codex is stronger when you prioritize Cheapest input price, Free providers, Provider coverage, Recent tests. | Kat Coder Pro V2 Kat Coder Pro V2 does not clearly lead on the verified metrics here, so check provider-specific pricing before choosing. |
TL;DR: GPT-5.3 Codex leads across 74 verifiable data points, including pricing, speed, latency, benchmarks, and provider examples.
Continue from GPT-5.3 Codex vs Kat Coder Pro V2 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. | Kat Coder Pro V2 exposes 256K tokens; notable signals: Text input, Text output, Tool calling, Structured outputs. |
|---|---|---|
| Developer | OpenAI | Kwaipilot |
| Context window | 400K tokens | 256K tokens |
| Max output | 128K tokens | 80K tokens |
| Released | Feb 2026 | Mar 2026 |
| Modalities | Input TextImageFile Output Text | Input Text Output Text |
| Features | Text inputImage inputFile inputText outputTool callingStructured outputsJSON modeReasoning | Text inputText outputTool callingStructured outputsJSON mode |
| Parameters | No data | No data |
| Tokenizer | GPT | Other |
| Knowledge cutoff | No data | No data |
| OpenRouter ID | openai/gpt-5.3-codex | kwaipilot/kat-coder-pro-v2 |
| References | No data | No data |
speed / latency
N/A / N/A
input / output
No data
Seamee API5 tests | GPT-5.3 Codex speed / latency 53 tok/s / 3889ms input / output No data | Kat Coder Pro V2 speed / latency N/A / N/A input / output No data |
|---|
AI API0 tests | GPT-5.3 Codex speed / latency N/A / N/A input / output No data | Kat Coder Pro V2 speed / latency N/A / N/A input / output No data |
|---|
Dext API0 tests | GPT-5.3 Codex openai/gpt-5.3-codex speed / latency N/A / N/A input / output $0.144/M/$1.15/M | Kat Coder Pro V2 kwaipilot/kat-coder-pro-v2 speed / latency N/A / N/A input / output $0.012/M/$0.049/M |
|---|
Futureppo0 tests | GPT-5.3 Codex speed / latency N/A / N/A input / output No data | Kat Coder Pro V2 speed / latency N/A / N/A input / output No data |
|---|
Rankings are based on community-submitted tests and periodic health probes. Advisory only, not official data.
