DeepSeek V3 0324 vs GPT-5.3-Codex
DeepSeek V3 0324 (2025) and GPT-5.3-Codex (2026) compare a standalone API model against a coding-specialized model. DeepSeek V3 0324 ships a 160K-token context window, while GPT-5.3-Codex ships a 400K-token context window. On SWE-bench Verified, GPT-5.3-Codex leads by 8.2 pts. On pricing, DeepSeek V3 0324 costs $0.27/1M input tokens versus $1.75/1M for the alternative. This page treats the result as workflow and deployment fit, not a universal model winner.
Treat this as a product-type comparison: DeepSeek V3 0324 is standalone API model, while GPT-5.3-Codex is coding-specialized model. Choose based on workflow fit before reading any benchmark or price row as decisive.
Decision scorecard
Local evidence first| Signal | DeepSeek V3 0324 | GPT-5.3-Codex |
|---|---|---|
| Product type | Standalone API model | Coding-specialized model |
| Best for | provider-routed production | custom coding agents, code generation, and tool loops |
| Decision fit | Coding, Agents, and Long context | Coding, RAG, and Agents |
| Context window | 160K | 400K |
| Cheapest output | $1.12/1M tokens | $14/1M tokens |
| Provider routes | 3 tracked | 3 tracked |
| Shared benchmarks | 1 rows | SWE-bench Verified leader |
Decision tradeoffs
- DeepSeek V3 0324 has the lower cheapest tracked output price at $1.12/1M tokens.
- Local decision data tags DeepSeek V3 0324 for Coding, Agents, and Long context.
- GPT-5.3-Codex leads the largest shared benchmark signal on SWE-bench Verified by 8.2 points.
- GPT-5.3-Codex has the larger context window for long prompts, retrieval packs, or transcript analysis.
- GPT-5.3-Codex uniquely exposes Vision, Reasoning, and Function calling in local model data.
- Local decision data tags GPT-5.3-Codex for Coding, RAG, and Agents.
Monthly cost at traffic
Estimate token spend from the cheapest tracked input and output route or tier on this page.
DeepSeek V3 0324
$496
Cheapest tracked route/tier: Novita AI
GPT-5.3-Codex
$4,900
Cheapest tracked route/tier: OpenRouter
Estimated monthly gap: $4,404. Batch, cache, alternate speed tiers, and negotiated pricing are excluded from this local estimate.
Switch friction
- No overlapping tracked provider route is sourced for DeepSeek V3 0324 and GPT-5.3-Codex; plan for SDK, billing, or endpoint changes.
- GPT-5.3-Codex is $12.88/1M tokens higher on cheapest tracked output pricing, so quality gains need to justify the spend.
- GPT-5.3-Codex adds Vision, Reasoning, and Function calling in local capability data.
- No overlapping tracked provider route is sourced for GPT-5.3-Codex and DeepSeek V3 0324; plan for SDK, billing, or endpoint changes.
- DeepSeek V3 0324 is $12.88/1M tokens lower on cheapest tracked output pricing before cache, batch, or negotiated discounts.
- Check replacement coverage for Vision, Reasoning, and Function calling before moving production traffic.
Specs
| Specification | ||
|---|---|---|
| Released | 2025-03-24 | 2026-02-05 |
| Context window | 160K | 400K |
| Parameters | 671B | — |
| Architecture | decoder only | decoder only |
| License | Open Source | Proprietary |
| Knowledge cutoff | - | 2025-08 |
Pricing and availability
| Pricing attribute | DeepSeek V3 0324 | GPT-5.3-Codex |
|---|---|---|
| Input price | $0.27/1M tokens | $1.75/1M tokens |
| Output price | $1.12/1M tokens | $14/1M tokens |
| Providers |
Capabilities
| Capability | DeepSeek V3 0324 | GPT-5.3-Codex |
|---|---|---|
| Vision | No | Yes |
| Multimodal | No | No |
| Reasoning | No | Yes |
| Function calling | No | Yes |
| Tool use | No | Yes |
| Structured outputs | No | Yes |
| Code execution | No | Yes |
| IDE integration | No | No |
| Computer use | No | No |
| Parallel agents | No | No |
Benchmarks
| Benchmark | DeepSeek V3 0324 | GPT-5.3-Codex |
|---|---|---|
| SWE-bench Verified | 76.8 | 85.0 |
Deep dive
On shared benchmark coverage, SWE-bench Verified has DeepSeek V3 0324 at 76.8 and GPT-5.3-Codex at 85, with GPT-5.3-Codex ahead by 8.2 points. The largest visible gap is 8.2 points on SWE-bench Verified, which matters most when that benchmark mirrors your workload. Treat isolated benchmark wins as directional, because provider routing, prompt style, and tool access can move real application results.
The capability footprint differs most on vision: GPT-5.3-Codex, reasoning mode: GPT-5.3-Codex, function calling: GPT-5.3-Codex, tool use: GPT-5.3-Codex, structured outputs: GPT-5.3-Codex, and code execution: GPT-5.3-Codex. Both models share the core language-model surface, so the practical split is not just feature count. Use those differences to decide whether the page is about raw model quality, agentic coding support, multimodal ingestion, or predictable structured API behavior.
For cost, DeepSeek V3 0324 lists $0.27/1M input and $1.12/1M output tokens on the cheapest tracked provider, while GPT-5.3-Codex lists $1.75/1M input and $14/1M output tokens on the cheapest tracked provider. A 70/30 input-output blend puts DeepSeek V3 0324 lower by about $4.90 per million blended tokens. Availability is 3 providers versus 3, so concentration risk also matters.
Choose DeepSeek V3 0324 when provider fit and lower input-token cost are central to the workload. Choose GPT-5.3-Codex when coding workflow support and larger context windows are more important. For production, rerun your own prompts through the exact provider, region, and tool stack you plan to ship.
FAQ
Which has a larger context window, DeepSeek V3 0324 or GPT-5.3-Codex?
GPT-5.3-Codex supports 400K tokens, while DeepSeek V3 0324 supports 160K tokens. That gap matters most for long documents, large codebases, retrieval-heavy agents, and conversations where earlier context must remain visible.
Which is cheaper, DeepSeek V3 0324 or GPT-5.3-Codex?
DeepSeek V3 0324 is cheaper on tracked token pricing. DeepSeek V3 0324 costs $0.27/1M input and $1.12/1M output tokens. GPT-5.3-Codex costs $1.75/1M input and $14/1M output tokens. Provider discounts or batch pricing can still change the final bill.
Is DeepSeek V3 0324 or GPT-5.3-Codex open source?
DeepSeek V3 0324 is listed under Open Source. GPT-5.3-Codex is listed under Proprietary. License labels affect whether you can self-host, redistribute weights, or rely only on hosted APIs, so confirm the upstream license before deployment.
Which is better for vision, DeepSeek V3 0324 or GPT-5.3-Codex?
GPT-5.3-Codex has the clearer documented vision signal in this comparison. If vision is mission-critical, validate it against the provider endpoint because model-level support and API-level exposure can differ. Use this as a quick comparison signal, then confirm the provider-specific limits before committing to production.
Which is better for reasoning mode, DeepSeek V3 0324 or GPT-5.3-Codex?
GPT-5.3-Codex has the clearer documented reasoning mode signal in this comparison. If reasoning mode is mission-critical, validate it against the provider endpoint because model-level support and API-level exposure can differ.
Where can I run DeepSeek V3 0324 and GPT-5.3-Codex?
DeepSeek V3 0324 is available on Fireworks AI, Microsoft Foundry, and Novita AI. GPT-5.3-Codex is available on OpenRouter, OpenAI API, and Vercel AI Gateway. Provider coverage can affect latency, region availability, compliance posture, and fallback options.
Continue comparing
Last reviewed: 2026-05-22. Data sourced from public model cards and provider documentation.