Model comparison
DeepSeek V4 Pro vs GPT-5.3-Codex
DeepSeek against OpenAI, compared on context, price, and verified benchmark results.
Catalog record checked September 3, 2026Individual provider fields may changeEvidence confidence: High — see receipts below
DeepSeek
DeepSeek V4 Pro
Frontier · Open weights
OpenAI
GPT-5.3-Codex
Frontier
| Specification | DeepSeek V4 Pro | GPT-5.3-Codex |
|---|---|---|
| Provider | DeepSeek | OpenAI |
| Tier | Frontier | Frontier |
| Context window | Winner: 1M | 400K |
| Max output | Winner: 384K | 128K |
| Input / 1M tokens | Winner: $1.32 | $1.75 |
| Output / 1M tokens | Winner: $3.96 | $14 |
| Weights | Open | Closed |
| Parameters | 1.6T total / 49B active (MoE) | Not disclosedUnverified |
| Reasoning levels | low, high, max | none, low, medium, high, xhigh, max |
| Modalities | text | text, image |
| License | MIT | Not disclosedUnverified |
| API model id | deepseek-v4-pro | gpt-5.3-codex |
| Released | April 24, 2026 | February 5, 2026 |
| Artificial Analysis Intelligence Index (2026-08-14) | 53 | Not verifiedUnverified |
| Artificial Analysis Intelligence Index [high] (2026-08-14) | Not verifiedUnverified | 52 |
| SWE-bench Verified (2026-04-24) | 80.6 | Not verifiedUnverified |
| GPQA Diamond (2026-04-24) | 90.1 | Not verifiedUnverified |
| Humanity's Last Exam (2026-04-24) | 48.2 | Not verifiedUnverified |
| MMLU-Pro (2026-04-24) | 87.5 | Not verifiedUnverified |
Prices are USD per million tokens at standard rates, excluding batch and caching discounts. Bold indicates the better figure where one is objectively better. Values we could not confirm from the provider are shown as “Not verified” rather than estimated.
Benchmark receipts
- 2026-08-14: Artificial AnalysisComposite index blending reasoning, knowledge, and coding evals into one 0–100 score. Comparability: directly comparable — AA occasionally rebaselines the index scale between snapshots — a score captured on one date is only comparable to same-snapshot scores (check measuredAt).
- 2026-04-24: DeepSeek V4 Pro HF model card (vendor, Think Max, exact match)Real GitHub issue resolution: does the model's patch pass the hidden tests. Comparability: comparable with caveat — Post-audit vendor claims and pre-audit scores sit on different task trust levels; scaffolding (agent harness, compute budget) also dominates results. Never aggregate across scaffolds.
Pricing tiers: DeepSeek V4 Pro: Official peak rates $1.32/$3.96 per MTok; off-peak $0.66/$1.98 (cache-miss). Open weights (MIT). 1.6T/49B active MoE. · GPT-5.3-Codex: Standard $1.75/$14 per MTok; cached input $0.175/MTok; Fast mode $3.50/$28. Purpose-built for the Codex agent.
DeepSeek V4 Pro
DeepSeek V4 Pro is the open-weight (MIT) flagship with a 1M-token context at a fraction of frontier API cost.
Best for
- Cost-sensitive hosted agents
- Open-weight deployments
- High-volume coding
Watch out
Self-hosting needs datacentre VRAM; hosted rates vary by provider. Price single-source — verify.
GPT-5.3-Codex
GPT-5.3-Codex is OpenAI's coding-specialised model powering the Codex agent at $1.75/$14.
Best for
- Autonomous coding
- Repo-scale refactors
- Test generation
Watch out
Tuned for coding, not general chat; use GPT-5.6 for broad reasoning.
When the cheaper one wins
DeepSeek V4 Pro is cheaper on output at $3.96 per million tokens against $14 for GPT-5.3-Codex — about 3.5×. Use the cheaper tier for classification, extraction, summarisation, and any task where the expensive model’s extra score does not change the accepted output. The expensive one only pays if your hardest task actually fails on the cheap tier. These are standard-tier API rates, excluding batch and cache discounts.
Run the model pickerEvidence confidence: High
How strong and complete the evidence behind this comparison is — not a prediction of which model is better.
- Pricing verified on both sides — Input and output rates are verified for both models.
- 4/5 core specs verified on both sides — Not published for at least one side: parameter count.
- 1 shared named benchmark (scores match) — Measured on: Artificial Analysis Intelligence Index — scores are equivalent, so the benchmark does not separate the pair.
- Verified within the last 90 days — Newest catalog check was 8 days ago.
- Both models carry source citations — Each side has at least two catalog sources on record.
Source receipts
Each catalog figure was checked against the provider or an independent second source on the date shown.
- DeepSeek V4 Pro: DeepSeek — V4 news (accessed 2026-08-29)
- DeepSeek V4 Pro: DeepSeek API pricing (accessed 2026-08-29)
- GPT-5.3-Codex: OpenAI — Introducing GPT-5.3-Codex (accessed 2026-08-29)
- GPT-5.3-Codex: OpenAI API pricing (gpt-5.3-codex $1.75/$14) (accessed 2026-08-29)
Related comparisons
- Claude Fable 5.1 vs DeepSeek V4 Pro
- Claude Fable 5.1 vs GPT-5.3-Codex
- Claude Fable 5 vs DeepSeek V4 Pro
- Claude Fable 5 vs GPT-5.3-Codex
- Claude Mythos 5.1 vs DeepSeek V4 Pro
- Claude Mythos 5.1 vs GPT-5.3-Codex
Diving deeper on one model? DeepSeek V4 Pro · GPT-5.3-Codex
Common questions
DeepSeek V4 Pro vs GPT-5.3-Codex
Answered from the verified figures on this page rather than general guidance.
Is DeepSeek V4 Pro or GPT-5.3-Codex cheaper for input?
DeepSeek V4 Pro is cheaper at $1.32 per million input tokens, against $1.75 for GPT-5.3-Codex — roughly 1.3× the price. Output tokens usually dominate a real bill, so weigh the output rate more heavily than the input rate. These are base rates; DeepSeek V4 Pro has tiered pricing: Official peak rates $1.32/$3.96 per MTok; off-peak $0.66/$1.98 (cache-miss). Open weights (MIT). 1.6T/49B active MoE. GPT-5.3-Codex has tiered pricing: Standard $1.75/$14 per MTok; cached input $0.175/MTok; Fast mode $3.50/$28. Purpose-built for the Codex agent.
Is DeepSeek V4 Pro or GPT-5.3-Codex cheaper for output?
DeepSeek V4 Pro is cheaper at $3.96 per million output tokens, against $14 for GPT-5.3-Codex — roughly 3.5× the price. Output tokens usually dominate a real bill, so weigh the output rate more heavily than the input rate. These are base rates; DeepSeek V4 Pro has tiered pricing: Official peak rates $1.32/$3.96 per MTok; off-peak $0.66/$1.98 (cache-miss). Open weights (MIT). 1.6T/49B active MoE. GPT-5.3-Codex has tiered pricing: Standard $1.75/$14 per MTok; cached input $0.175/MTok; Fast mode $3.50/$28. Purpose-built for the Codex agent.
Which has the larger context window, DeepSeek V4 Pro or GPT-5.3-Codex?
DeepSeek V4 Pro accepts 1M tokens against 400K for GPT-5.3-Codex. This only matters if you routinely send very long documents or large codebases.
Do DeepSeek V4 Pro and GPT-5.3-Codex support the same reasoning levels?
DeepSeek V4 Pro exposes low, high, max, while GPT-5.3-Codex exposes none, low, medium, high, xhigh, max.
Should I use DeepSeek V4 Pro or GPT-5.3-Codex?
Both sit in the frontier tier, so the choice usually comes down to price and context rather than capability. DeepSeek V4 Pro suits cost-sensitive hosted agents; GPT-5.3-Codex suits autonomous coding.
Can I self-host DeepSeek V4 Pro or GPT-5.3-Codex?
DeepSeek V4 Pro publishes open weights, but self-hosting and third-party provider access depend on the licence, hardware, serving support, and availability. GPT-5.3-Codex is a closed model whose supported access paths are controlled by its provider.
Next step
Choosing between them
The verified figures that separate this pair, computed from the catalog rather than restated boilerplate.
- Input price: DeepSeek V4 Pro costs $1.32 per 1M tokens versus $1.75 for GPT-5.3-Codex — a 1.3x difference at the headline tier.
- Context: DeepSeek V4 Pro takes 1M against 400K for GPT-5.3-Codex — only decisive if your prompts approach the smaller window.
- Measured capability: DeepSeek V4 Pro leads Artificial Analysis Intelligence Index 53 to 52 (measured 2026-08-14).
- Deployment: DeepSeek V4 Pro publishes weights you can self-host; the other is API-only.
Choosing a harness rather than a model — Cursor, Copilot, Claude Code, Windsurf, or Lovable? Compare agentic harnesses · Latest releases.