LLM Reference

Gemini 2.5 Pro vs GPT-5.2 Codex

Gemini 2.5 Pro (2025) and GPT-5.2 Codex (2025) compare a standalone API model against a coding-specialized model. Gemini 2.5 Pro ships a 1m-token context window, while GPT-5.2 Codex ships a 400k-token context window. On SWE-bench Verified, GPT-5.2 Codex leads by 9 pts. On pricing, Gemini 2.5 Pro ranges from $1.25 to $2.50/1M input tokens by tier; GPT-5.2 Codex costs $1.75/1M input tokens. 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 is standalone API model, while GPT-5.2 Codex is coding-specialized model. Choose based on workflow fit before reading any benchmark or price row as decisive.

Decision scorecard

Local evidence first
SignalGemini 2.5 ProGPT-5.2 Codex
Product typeStandalone API modelCoding-specialized model
Best forreasoning-heavy apps, multimodal apps, and tool-calling agentscustom coding agents, code generation, and tool loops
Decision fitCoding, RAG, and AgentsCoding, RAG, and Agents
Context window1m400k
Cheapest output$10/1M tokens$14/1M tokens
Provider routes4 tracked2 tracked
Shared benchmarks2 sharedSWE-bench Verified leader

Decision tradeoffs

Choose Gemini 2.5 Pro when...
  • Gemini 2.5 Pro has the larger context window for long prompts, retrieval packs, or transcript analysis.
  • Gemini 2.5 Pro has the lower cheapest tracked output price at $10/1M tokens.
  • Gemini 2.5 Pro has broader tracked provider coverage for fallback and procurement flexibility.
  • Local decision data tags Gemini 2.5 Pro for Coding, RAG, and Agents.
Choose GPT-5.2 Codex when...
  • GPT-5.2 Codex holds a shared-benchmark lead on SWE-bench Verified, ahead by 9 points.
  • Local decision data tags GPT-5.2 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.

Lower estimate Gemini 2.5 Pro

Gemini 2.5 Pro

$3,500

Cheapest tracked route/tier: Google AI Studio <=200K tokens

GPT-5.2 Codex

$4,900

Cheapest tracked route/tier: Vercel AI Gateway

Estimated monthly gap: $1,400. Batch, cache, alternate speed tiers, and negotiated pricing are excluded from this local estimate.

Switch friction

Gemini 2.5 Pro -> GPT-5.2 Codex
  • Provider overlap exists on Vercel AI Gateway; start route-level A/B tests there.
  • GPT-5.2 Codex is $4/1M tokens higher on cheapest tracked output pricing, so quality gains need to justify the spend.
GPT-5.2 Codex -> Gemini 2.5 Pro
  • Provider overlap exists on Vercel AI Gateway; start route-level A/B tests there.
  • Gemini 2.5 Pro is $4/1M tokens lower on cheapest tracked output pricing before cache, batch, or negotiated discounts.

Specs

Specification
Released2025-06-172025-12-18
Context window1m400k
Parameters
ArchitectureDecoder OnlyDecoder Only
LicenseProprietaryProprietary
OpennessProprietaryProprietary
WeightsNot releasedNot released
CodeUnknownUnknown
Commercial useCommercial use: conditionalCommercial use: conditional
Knowledge cutoff2025-012025-08

Pricing and availability

Pricing attributeGemini 2.5 ProGPT-5.2 Codex
Input price
<=200K tokens
$1.25/1M tokens
Standard Gemini 2.5 Pro pricing for prompts up to 200K tokens.
>200K tokens
$2.50/1M tokens
Higher Gemini 2.5 Pro tier for prompts above 200K tokens.
$1.75/1M tokens
Output price
<=200K tokens
$10/1M tokens
Standard Gemini 2.5 Pro pricing for prompts up to 200K tokens.
>200K tokens
$15/1M tokens
Higher Gemini 2.5 Pro tier for prompts above 200K tokens.
$14/1M tokens
Providers

Capabilities

CapabilityGemini 2.5 ProGPT-5.2 Codex
VisionYesYes
MultimodalYesYes
ReasoningYesYes
Function callingYesYes
Tool useYesYes
Structured outputsYesYes
Code executionYesYes
IDE integrationNoNo
Computer useNoNo
Parallel agentsNoNo

Benchmarks

BenchmarkGemini 2.5 ProGPT-5.2 Codex
SWE-bench Verified63.872.8
Terminal-Bench 2.032.664.0

Deep dive

On shared benchmark coverage, SWE-bench Verified has Gemini 2.5 Pro at 63.8 and GPT-5.2 Codex at 72.8, with GPT-5.2 Codex ahead by 9 points; Terminal-Bench 2.0 has Gemini 2.5 Pro at 32.6 and GPT-5.2 Codex at 64, with GPT-5.2 Codex ahead by 31.4 points. The largest visible gap is 31.4 points on Terminal-Bench 2.0, 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 is close: both models cover vision, multimodal input, reasoning mode, function calling, and tool use. That makes context budget, benchmark fit, and provider maturity more important than a simple checklist. If your application depends on one integration detail, verify it against the provider route you plan to use, not just the base model listing.

For cost, Gemini 2.5 Pro lists tiered pricing: <=200K tokens is $1.25/1M input and $10/1M output; >200K tokens is $2.50/1M input and $15/1M output, while GPT-5.2 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 lower by about $1.55 per million blended tokens. For tiered rows, this cheapest-track view can understate interactive or fast-lane spend, so compare the tier you will actually use. Availability is 4 providers versus 2, so concentration risk also matters.

Choose Gemini 2.5 Pro when coding workflow support, larger context windows, and lower cheapest-tier input-token cost are central to the workload. Choose GPT-5.2 Codex when coding workflow support 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, Gemini 2.5 Pro or GPT-5.2 Codex?

Gemini 2.5 Pro supports 1m tokens, while GPT-5.2 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 or GPT-5.2 Codex?

Gemini 2.5 Pro lists tiered pricing: <=200K tokens is $1.25/1M input and $10/1M output; >200K tokens is $2.50/1M input and $15/1M output. GPT-5.2 Codex lists $1.75/1M input and $14/1M output tokens on the cheapest tracked provider. Compare the tier you will actually use; cheap async pricing can overstate savings for interactive workflows. Provider discounts or batch pricing can still change the final bill.

Is Gemini 2.5 Pro or GPT-5.2 Codex open source?

Gemini 2.5 Pro is listed under Proprietary. GPT-5.2 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 or GPT-5.2 Codex?

Both Gemini 2.5 Pro and GPT-5.2 Codex expose vision. The better choice depends on benchmark fit, context budget, pricing, and whether your provider route exposes the same capability surface. Use this as a quick comparison signal, then confirm the provider-specific limits before committing to production.

Which is better for multimodal input, Gemini 2.5 Pro or GPT-5.2 Codex?

Both Gemini 2.5 Pro and GPT-5.2 Codex expose multimodal input. The better choice depends on benchmark fit, context budget, pricing, and whether your provider route exposes the same capability surface.

Where can I run Gemini 2.5 Pro and GPT-5.2 Codex?

Gemini 2.5 Pro is available on Google AI Studio, GCP Vertex AI, OpenRouter, and Vercel AI Gateway. GPT-5.2 Codex is available on Vercel AI Gateway and OpenAI API. Provider coverage can affect latency, region availability, compliance posture, and fallback options.

Continue comparing

Last reviewed: 2026-06-30. Data sourced from public model cards and provider documentation.