DeepSeek V4 Pro vs GPT-5.3 Codex
DeepSeek V4 Pro 
GPT-5.3 Codex Verdict
- GPT-5.3 Codex (xhigh) leads on quality: 65.4 vs 64.2.
- DeepSeek V4 Pro (max) is stronger in composite, instruction following, maths.
- GPT-5.3 Codex (xhigh) is stronger in agents & tools, coding, knowledge, long context, reasoning, multimodal.
- DeepSeek V4 Pro (max) is 8.8× cheaper ($0.544 vs $4.81 per 1M blended).
- GPT-5.3 Codex (xhigh) streams 1.5× faster (125 vs 81 tokens per second).
| Metric | DeepSeek V4 Pro (max) | GPT-5.3 Codex (xhigh) |
|---|---|---|
| BenchLeader Index | 64.2 | 65.4 |
| Agents & tools score | 70.2 | 79.8 |
| Coding score | 58.8 | 61.7 |
| Composite score | 75.0 | 70.2 |
| Instruction following score | 74.3 | 73.4 |
| Knowledge score | 58.1 | 69.4 |
| Long context score | 66.6 | 68.2 |
| Maths score | 53.7 | – |
| Reasoning score | 70.9 | 74.4 |
| Multimodal score | – | 63.0 |
| Blended price $/M | $0.544 | $4.81 |
| Output speed | 81 tok/s | 125 tok/s |
| Time to first answer | 55.6 s | 50.8 s |
| Context window | 1M | 400k |
| GPQA Diamond | 89.7% | – |
| FrontierMath Tiers 1–3 | 45.3% | – |
| FrontierMath Tier 4 | 2.4% | – |
| OTIS Mock AIME | 96.7% | – |
| SWE-bench Verified (Epoch) | 77.6% | – |
| SimpleQA Verified | 47.0% | – |
| SciCode | 50.0% | – |
| WeirdML | 48.9% | 77.9% |
| ProofBench | 16.0% | – |
| AA Intelligence Index | 36.3 | 32.5 |
| IFBench | 76.5% | 75.4% |
| AA-LCR | 80.3% | 83.3% |
| MMMU-Pro | – | 78.5% |
| AA-Omniscience | 0.8 | 10.9 |
| Terminal-Bench Hard | 46.2% | 53.0% |
| GPQA Diamond (AA) | 92.8% | 91.5% |
| Humanity's Last Exam (AA) | 41.0% | 42.5% |
| SciCode (AA) | 51.0% | – |
| τ²-Bench Telecom (AA) | 96.2% | 86.0% |
| LiveCodeBench | 87.5% | 87.3% |
| MMLU-Pro | 87.3% | – |
| IOI | – | 53.8% |
| LegalBench | 80.3% | – |
| CorpFin | 61.4% | – |
| TaxEval | 72.1% | – |
| SWE-bench (Vals) | 77.4% | 78.0% |
| GPQA Diamond (Vals) | 89.4% | – |
| Vals Index | 42.9 | – |
| AIME 2026 | 96.7% | – |
| HMMT February 2026 | 93.9% | – |
| MathArena Apex | 28.1% | – |
| CritPt | 18.0% | 16.9% |
| GDPval (AA) | 49.7% | – |
| τ²-Bench Banking (AA) | 39.6% | – |
| ITBench SRE (AA) | 38.3% | – |
| Analyst Agent (AA) | 18.8% | – |
| APEX-Agents (AA) | 24.3% | – |
| CaseLaw v2 | 59.4% | – |
| Code Migration | 26.2% | – |
| Excel Modeling Benchmark | 51.6% | – |
| Finance Agent v2 | 44.1% | – |
| Harvey's Legal Agent Benchmark | 3.8% | – |
| Legal Research Bench | 23.1% | – |
| MedCode | 40.5% | – |
| MedScribe | 75.1% | – |
| ProgramBench | 0.0% | – |
| Public Benefits Bench | 62.9% | – |
| SkillsBench | 51.3% | – |
| Vibe Code Bench v1.1 | 49.9% | 61.8% |
| Chess Puzzles | 20.0% | – |
| LMCA | 41.2% | – |
| DTBench | 90.7% | – |
| ALE-Bench | – | 1655.2 |
Data as of 2026-09-19. Best configuration of each model; every score links to its source on the model pages.
DeepSeek V4 Pro vs GPT-5.3 Codex: questions
- Is DeepSeek V4 Pro better than GPT-5.3 Codex?
- GPT-5.3 Codex (xhigh) leads on quality: 65.4 vs 64.2. The BenchLeader Index combines every independent quality benchmark; GPT-5.3 Codex (xhigh) is ahead overall as of 2026-09-19, but check the category scores for your use.
- Is DeepSeek V4 Pro better than GPT-5.3 Codex for coding?
- GPT-5.3 Codex scores higher in coding (62 vs 59 on the category index, where 50 is average).
- Is DeepSeek V4 Pro better than GPT-5.3 Codex for agentic tasks?
- GPT-5.3 Codex scores higher in agentic tasks (80 vs 70 on the category index, where 50 is average).
- Which is cheaper, DeepSeek V4 Pro or GPT-5.3 Codex?
- DeepSeek V4 Pro is cheaper: $0.544 against $4.81 per million tokens, blended at three input tokens per output token.
- Which is faster, DeepSeek V4 Pro or GPT-5.3 Codex?
- GPT-5.3 Codex streams faster: 125 against 81 output tokens per second.
- Which has the larger context window?
- DeepSeek V4 Pro accepts more context: 1M against 400k tokens.