LLM ReferenceLLM Reference

Gemini 2.5 Pro vs Grok-3

Gemini 2.5 Pro (2025) and Grok-3 (2025) are frontier reasoning models from Google DeepMind and xAI. Gemini 2.5 Pro ships a 1M-token context window, while Grok-3 ships a 1M-token context window. On MMLU PRO, Gemini 2.5 Pro leads by 6.3 pts. On pricing, Grok-3 costs $0.8/1M input tokens versus $1.25/1M for the alternative. This comparison covers specs, pricing, capabilities, benchmarks, provider availability, and production fit.

Grok-3 is ~56% cheaper at $0.8/1M; pay for Gemini 2.5 Pro only for coding workflow support.

Decision scorecard

Local evidence first
SignalGemini 2.5 ProGrok-3
Decision fitCoding, RAG, and AgentsCoding, RAG, and Agents
Context window1M1M
Cheapest output$10/1M tokens$2.4/1M tokens
Provider routes3 tracked3 tracked
Shared benchmarksMMLU PRO leader2 rows

Decision tradeoffs

Choose Gemini 2.5 Pro when...
  • Gemini 2.5 Pro leads the largest shared benchmark signal on MMLU PRO by 6.3 points.
  • Gemini 2.5 Pro uniquely exposes Code execution in local model data.
  • Local decision data tags Gemini 2.5 Pro for Coding, RAG, and Agents.
Choose Grok-3 when...
  • Grok-3 leads the largest shared benchmark signal on Chatbot Arena by 7 points.
  • Grok-3 has the lower cheapest tracked output price at $2.4/1M tokens.
  • Grok-3 uniquely exposes Reasoning in local model data.
  • Local decision data tags Grok-3 for Coding, RAG, and Agents.

Monthly cost at traffic

Estimate token spend from the cheapest tracked input and output prices on this page.

Lower estimate Grok-3

Gemini 2.5 Pro

$3,500

Cheapest tracked route: Google AI Studio

Grok-3

$1,240

Cheapest tracked route: Chutes AI

Estimated monthly gap: $2,260. Batch, cache, and negotiated pricing are excluded from this local estimate.

Switch friction

Gemini 2.5 Pro -> Grok-3
  • Provider overlap exists on OpenRouter; start route-level A/B tests there.
  • Grok-3 is $7.6/1M tokens lower on cheapest tracked output pricing before cache, batch, or negotiated discounts.
  • Check replacement coverage for Code execution before moving production traffic.
  • Grok-3 adds Reasoning in local capability data.
Grok-3 -> Gemini 2.5 Pro
  • Provider overlap exists on OpenRouter; start route-level A/B tests there.
  • Gemini 2.5 Pro is $7.6/1M tokens higher on cheapest tracked output pricing, so quality gains need to justify the spend.
  • Check replacement coverage for Reasoning before moving production traffic.
  • Gemini 2.5 Pro adds Code execution in local capability data.

Specs

Specification
Released2025-06-172025-04-09
Context window1M1M
Parameters1B
Architecturedecoder only-
LicenseProprietaryProprietary
Knowledge cutoff2025-012025-04

Pricing and availability

Pricing attributeGemini 2.5 ProGrok-3
Input price$1.25/1M tokens$0.8/1M tokens
Output price$10/1M tokens$2.4/1M tokens
Providers

Capabilities

CapabilityGemini 2.5 ProGrok-3
VisionYesYes
MultimodalYesYes
ReasoningNoYes
Function callingYesYes
Tool useYesYes
Structured outputsYesYes
Code executionYesNo

Benchmarks

BenchmarkGemini 2.5 ProGrok-3
MMLU PRO86.279.9
Chatbot Arena1398.01405.0

Deep dive

On shared benchmark coverage, MMLU PRO has Gemini 2.5 Pro at 86.2 and Grok-3 at 79.9, with Gemini 2.5 Pro ahead by 6.3 points; Chatbot Arena has Gemini 2.5 Pro at 1398 and Grok-3 at 1405, with Grok-3 ahead by 7 points. The largest visible gap is 7 points on Chatbot Arena, 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 reasoning mode: Grok-3 and code execution: Gemini 2.5 Pro. Both models share vision, multimodal input, function calling, and tool use, 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 lists $1.25/1M input and $10/1M output tokens, while Grok-3 lists $0.8/1M input and $2.4/1M output tokens on the cheapest tracked provider. A 70/30 input-output blend puts Grok-3 lower by about $2.6 per million blended tokens. Availability is 3 providers versus 3, so concentration risk also matters.

Choose Gemini 2.5 Pro when coding workflow support are central to the workload. Choose Grok-3 when reasoning depth and lower input-token cost 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 Grok-3?

Gemini 2.5 Pro supports 1M tokens, while Grok-3 supports 1M 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 Grok-3?

Grok-3 is cheaper on tracked token pricing. Gemini 2.5 Pro costs $1.25/1M input and $10/1M output tokens. Grok-3 costs $0.8/1M input and $2.4/1M output tokens. Provider discounts or batch pricing can still change the final bill.

Is Gemini 2.5 Pro or Grok-3 open source?

Gemini 2.5 Pro is listed under Proprietary. Grok-3 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 Grok-3?

Both Gemini 2.5 Pro and Grok-3 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 Grok-3?

Both Gemini 2.5 Pro and Grok-3 expose multimodal input. 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.

Where can I run Gemini 2.5 Pro and Grok-3?

Gemini 2.5 Pro is available on Google AI Studio, GCP Vertex AI, and OpenRouter. Grok-3 is available on OpenRouter, xAI Console, and Chutes AI. Provider coverage can affect latency, region availability, compliance posture, and fallback options.

Continue comparing

Last reviewed: 2026-05-14. Data sourced from public model cards and provider documentation.