Gemini 2.5 Pro Preview 06-05 vs Grok 4.20
Gemini 2.5 Pro Preview 06-05 (2025) and Grok 4.20 (2026) are frontier reasoning models from Google DeepMind and xAI. Gemini 2.5 Pro Preview 06-05 ships a 1m-token context window, while Grok 4.20 ships a 1m-token context window. On Aider Polyglot, Grok 4.20 leads by 0.5 pts. On pricing, both list $1.25/1M input tokens on the cheapest tracked route. This comparison covers specs, pricing, API access, capabilities, benchmarks, input and output token costs, and production fit for coding and agent workloads.
Grok 4.20 is safer overall; choose Gemini 2.5 Pro Preview 06-05 when coding workflow support matters.
Decision scorecard
Local evidence first| Signal | Gemini 2.5 Pro Preview 06-05 | Grok 4.20 |
|---|---|---|
| Best for | multimodal apps and long-context analysis | reasoning-heavy apps, multimodal apps, and tool-calling agents |
| Decision fit | Coding, RAG, and Agents | Coding, RAG, and Agents |
| Context window | 1m | 1m |
| Cheapest output | $10/1M tokens | $2.50/1M tokens |
| Provider routes | 1 tracked | 2 tracked |
| Shared benchmarks | 1 rows | Aider Polyglot leader |
Decision tradeoffs
- Gemini 2.5 Pro Preview 06-05 uniquely exposes Code execution in local model data.
- Local decision data tags Gemini 2.5 Pro Preview 06-05 for Coding, RAG, and Agents.
- Grok 4.20 holds a shared-benchmark lead on Aider Polyglot, ahead by 0.5 points.
- Grok 4.20 has the lower cheapest tracked output price at $2.50/1M tokens.
- Grok 4.20 has broader tracked provider coverage for fallback and procurement flexibility.
- Grok 4.20 uniquely exposes Reasoning, Function calling, and Tool use in local model data.
- Local decision data tags Grok 4.20 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 06-05
$3,500
Cheapest tracked route/tier: OpenRouter
Grok 4.20
$1,625
Cheapest tracked route/tier: xAI Console
Estimated monthly gap: $1,875. 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.
- Grok 4.20 is $7.50/1M tokens lower on cheapest tracked output pricing before cache, batch, or negotiated discounts.
- Check replacement coverage for Code execution before moving production traffic.
- Grok 4.20 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 06-05 is $7.50/1M tokens higher on cheapest tracked output pricing, so quality gains need to justify the spend.
- Check replacement coverage for Reasoning, Function calling, and Tool use before moving production traffic.
- Gemini 2.5 Pro Preview 06-05 adds Code execution in local capability data.
Specs
| Specification | ||
|---|---|---|
| Released | 2025-03-25 | 2026-02-17 |
| Context window | 1m | 1m |
| Parameters | — | — |
| Architecture | decoder only | - |
| License | Proprietary | Proprietary |
| Openness | Proprietary | Proprietary |
| Commercial use | Commercial use with conditions | Commercial use with conditions |
| Knowledge cutoff | - | 2024-11 |
Pricing and availability
| Pricing attribute | Gemini 2.5 Pro Preview 06-05 | Grok 4.20 |
|---|---|---|
| Input price | $1.25/1M tokens | $1.25/1M tokens |
| Output price | $10/1M tokens | $2.50/1M tokens |
| Providers |
Capabilities
| Capability | Gemini 2.5 Pro Preview 06-05 | Grok 4.20 |
|---|---|---|
| Vision | Yes | Yes |
| Multimodal | Yes | Yes |
| Reasoning | No | Yes |
| Function calling | No | Yes |
| Tool use | No | Yes |
| Structured outputs | Yes | Yes |
| Code execution | Yes | No |
| IDE integration | No | No |
| Computer use | No | No |
| Parallel agents | No | No |
Benchmarks
| Benchmark | Gemini 2.5 Pro Preview 06-05 | Grok 4.20 |
|---|---|---|
| Aider Polyglot | 79.1 | 79.6 |
Deep dive
On shared benchmark coverage, Aider Polyglot has Gemini 2.5 Pro Preview 06-05 at 79.1 and Grok 4.20 at 79.6, with Grok 4.20 ahead by 0.5 points. The largest visible gap is 0.5 points on Aider Polyglot, 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 4.20, function calling: Grok 4.20, tool use: Grok 4.20, and code execution: Gemini 2.5 Pro Preview 06-05. Both models share vision, multimodal input, 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 06-05 lists $1.25/1M input and $10/1M output tokens on the cheapest tracked provider, while Grok 4.20 lists $1.25/1M input and $2.50/1M output tokens on the cheapest tracked provider. A 70/30 input-output blend puts Grok 4.20 lower by about $2.25 per million blended tokens. Availability is 1 providers versus 2, so concentration risk also matters.
Choose Gemini 2.5 Pro Preview 06-05 when coding workflow support are central to the workload. Choose Grok 4.20 when reasoning depth 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.
FAQ
Which has a larger context window, Gemini 2.5 Pro Preview 06-05 or Grok 4.20?
Gemini 2.5 Pro Preview 06-05 supports 1m tokens, while Grok 4.20 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 Preview 06-05 or Grok 4.20?
Grok 4.20 is cheaper on tracked token pricing. Gemini 2.5 Pro Preview 06-05 costs $1.25/1M input and $10/1M output tokens. Grok 4.20 costs $1.25/1M input and $2.50/1M output tokens. Provider discounts or batch pricing can still change the final bill.
Is Gemini 2.5 Pro Preview 06-05 or Grok 4.20 open source?
Gemini 2.5 Pro Preview 06-05 is listed under Proprietary. Grok 4.20 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 06-05 or Grok 4.20?
Both Gemini 2.5 Pro Preview 06-05 and Grok 4.20 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 06-05 or Grok 4.20?
Both Gemini 2.5 Pro Preview 06-05 and Grok 4.20 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 Preview 06-05 and Grok 4.20?
Gemini 2.5 Pro Preview 06-05 is available on OpenRouter. Grok 4.20 is available on xAI Console and OpenRouter. Provider coverage can affect latency, region availability, compliance posture, and fallback options.
Continue comparing
Last reviewed: 2026-06-04. Data sourced from public model cards and provider documentation.