Gemini 2.5 Pro Preview 05-06 vs Grok 4.20
Gemini 2.5 Pro Preview 05-06 (2025) and Grok 4.20 (2026) are frontier reasoning models from Google DeepMind and xAI. Gemini 2.5 Pro Preview 05-06 ships a 1m-token context window, while Grok 4.20 ships a 1m-token context window. 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 05-06 when vision-heavy evaluation matters.
Decision scorecard
Local evidence first| Signal | Gemini 2.5 Pro Preview 05-06 | Grok 4.20 |
|---|---|---|
| Best for | multimodal apps and long-context analysis | reasoning-heavy apps, multimodal apps, and tool-calling agents |
| Decision fit | RAG, Long context, and Vision | 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 | 0 rows | 0 rows |
Decision tradeoffs
- Local decision data tags Gemini 2.5 Pro Preview 05-06 for RAG, Long context, and Vision.
- 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 05-06
$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.
- 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 05-06 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.
Specs
| Specification | ||
|---|---|---|
| Released | 2025-05-06 | 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 | 2025-01 | 2024-11 |
Pricing and availability
| Pricing attribute | Gemini 2.5 Pro Preview 05-06 | 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 05-06 | 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 | No | No |
| IDE integration | No | No |
| Computer use | No | No |
| Parallel agents | No | No |
Benchmarks
No shared benchmark rows are currently sourced for this pair.
Deep dive
The capability footprint differs most on reasoning mode: Grok 4.20, function calling: Grok 4.20, and tool use: Grok 4.20. 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 05-06 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 05-06 when vision-heavy evaluation 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. This keeps the decision grounded in measurable tradeoffs instead of brand-level assumptions. It also helps separate model capability from provider packaging, which can change cost and latency.
FAQ
Which has a larger context window, Gemini 2.5 Pro Preview 05-06 or Grok 4.20?
Gemini 2.5 Pro Preview 05-06 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 05-06 or Grok 4.20?
Grok 4.20 is cheaper on tracked token pricing. Gemini 2.5 Pro Preview 05-06 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 05-06 or Grok 4.20 open source?
Gemini 2.5 Pro Preview 05-06 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 05-06 or Grok 4.20?
Both Gemini 2.5 Pro Preview 05-06 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 05-06 or Grok 4.20?
Both Gemini 2.5 Pro Preview 05-06 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 05-06 and Grok 4.20?
Gemini 2.5 Pro Preview 05-06 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.