Gemini 2.5 Pro Preview 05-06 vs GPT-5.3-Codex
Gemini 2.5 Pro Preview 05-06 (2025) and GPT-5.3-Codex (2026) compare a standalone API model against a coding-specialized model. Gemini 2.5 Pro Preview 05-06 ships a 1m-token context window, while GPT-5.3-Codex ships a 400k-token context window. On pricing, Gemini 2.5 Pro Preview 05-06 costs $1.25/1M 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: Gemini 2.5 Pro Preview 05-06 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 | Gemini 2.5 Pro Preview 05-06 | GPT-5.3-Codex |
|---|---|---|
| Product type | Standalone API model | Coding-specialized model |
| Best for | multimodal apps and long-context analysis | custom coding agents, code generation, and tool loops |
| Decision fit | RAG, Long context, and Vision | Coding, RAG, and Agents |
| Context window | 1m | 400k |
| Cheapest output | $10/1M tokens | $14/1M tokens |
| Provider routes | 1 tracked | 3 tracked |
| Shared benchmarks | 0 rows | 0 rows |
Decision tradeoffs
- Gemini 2.5 Pro Preview 05-06 has the larger context window for long prompts, retrieval packs, or transcript analysis.
- Gemini 2.5 Pro Preview 05-06 has the lower cheapest tracked output price at $10/1M tokens.
- Gemini 2.5 Pro Preview 05-06 uniquely exposes Multimodal in local model data.
- Local decision data tags Gemini 2.5 Pro Preview 05-06 for RAG, Long context, and Vision.
- GPT-5.3-Codex has broader tracked provider coverage for fallback and procurement flexibility.
- GPT-5.3-Codex uniquely exposes Reasoning, Function calling, and Tool use 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.
Gemini 2.5 Pro Preview 05-06
$3,500
Cheapest tracked route/tier: OpenRouter
GPT-5.3-Codex
$4,900
Cheapest tracked route/tier: OpenRouter
Estimated monthly gap: $1,400. Batch, cache, alternate speed tiers, and negotiated pricing are excluded from this local estimate.
Switch friction
- Provider overlap exists on OpenRouter; start route-level A/B tests there.
- GPT-5.3-Codex is $4/1M tokens higher on cheapest tracked output pricing, so quality gains need to justify the spend.
- Check replacement coverage for Multimodal before moving production traffic.
- GPT-5.3-Codex adds Reasoning, Function calling, and Tool use in local capability data.
- Provider overlap exists on OpenRouter; start route-level A/B tests there.
- Gemini 2.5 Pro Preview 05-06 is $4/1M tokens lower on cheapest tracked output pricing before cache, batch, or negotiated discounts.
- Check replacement coverage for Reasoning, Function calling, and Tool use before moving production traffic.
- Gemini 2.5 Pro Preview 05-06 adds Multimodal in local capability data.
Specs
| Specification | ||
|---|---|---|
| Released | 2025-05-06 | 2026-02-05 |
| Context window | 1m | 400k |
| Parameters | — | — |
| Architecture | decoder only | decoder only |
| License | Proprietary | Proprietary |
| Openness | Proprietary | Proprietary |
| Commercial use | Commercial use with conditions | Commercial use with conditions |
| Knowledge cutoff | 2025-01 | 2025-08 |
Pricing and availability
| Pricing attribute | Gemini 2.5 Pro Preview 05-06 | GPT-5.3-Codex |
|---|---|---|
| Input price | $1.25/1M tokens | $1.75/1M tokens |
| Output price | $10/1M tokens | $14/1M tokens |
| Providers |
Capabilities
| Capability | Gemini 2.5 Pro Preview 05-06 | GPT-5.3-Codex |
|---|---|---|
| Vision | Yes | Yes |
| Multimodal | Yes | No |
| Reasoning | No | Yes |
| Function calling | No | Yes |
| Tool use | No | Yes |
| Structured outputs | Yes | Yes |
| Code execution | No | Yes |
| IDE integration | No | No |
| Computer use | No | Yes |
| Parallel agents | No | No |
Benchmarks
No shared benchmark rows are currently sourced for this pair.
Deep dive
The capability footprint differs most on multimodal input: Gemini 2.5 Pro Preview 05-06, reasoning mode: GPT-5.3-Codex, function calling: GPT-5.3-Codex, tool use: GPT-5.3-Codex, and code execution: GPT-5.3-Codex. Both models share vision and structured outputs, 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, Gemini 2.5 Pro Preview 05-06 lists $1.25/1M input and $10/1M 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 Gemini 2.5 Pro Preview 05-06 lower by about $1.55 per million blended tokens. Availability is 1 providers versus 3, so concentration risk also matters.
Choose Gemini 2.5 Pro Preview 05-06 when long-context analysis, larger context windows, and lower input-token cost are central to the workload. Choose GPT-5.3-Codex when coding workflow support and broader provider choice are more important. For production, rerun your own prompts through the exact provider, region, and tool stack you plan to ship. This keeps the decision grounded in measurable tradeoffs instead of brand-level assumptions.
FAQ
Which has a larger context window, Gemini 2.5 Pro Preview 05-06 or GPT-5.3-Codex?
Gemini 2.5 Pro Preview 05-06 supports 1m tokens, while GPT-5.3-Codex supports 400k tokens. That gap matters most for long documents, large codebases, retrieval-heavy agents, and conversations where earlier context must remain visible.
Which is cheaper, Gemini 2.5 Pro Preview 05-06 or GPT-5.3-Codex?
Gemini 2.5 Pro Preview 05-06 is cheaper on tracked token pricing. Gemini 2.5 Pro Preview 05-06 costs $1.25/1M input and $10/1M 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 Gemini 2.5 Pro Preview 05-06 or GPT-5.3-Codex open source?
Gemini 2.5 Pro Preview 05-06 is listed under Proprietary. 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, Gemini 2.5 Pro Preview 05-06 or GPT-5.3-Codex?
Both Gemini 2.5 Pro Preview 05-06 and GPT-5.3-Codex expose vision. The better choice depends on benchmark fit, context budget, pricing, and whether your provider route exposes the same capability surface.
Which is better for multimodal input, Gemini 2.5 Pro Preview 05-06 or GPT-5.3-Codex?
Gemini 2.5 Pro Preview 05-06 has the clearer documented multimodal input signal in this comparison. If multimodal input is mission-critical, validate it against the provider endpoint because model-level support and API-level exposure can differ.
Where can I run Gemini 2.5 Pro Preview 05-06 and GPT-5.3-Codex?
Gemini 2.5 Pro Preview 05-06 is available on OpenRouter. 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: 2026-06-10. Data sourced from public model cards and provider documentation.