Grok-3 vs o3
Grok-3 (2025) and o3 (2025) are frontier-tier reasoning models from xAI and OpenAI. Grok-3 ships a 131k-token context window, while o3 ships a 200k-token context window. On Google-Proof Q&A, o3 leads by 3.1 pts. On pricing, Grok-3 costs $0.80/1M input tokens versus $2/1M for the alternative. This comparison covers specs, pricing, API access, capabilities, benchmarks, input and output token costs, and production fit for coding and agent workloads.
Grok-3 is ~150% cheaper at $0.80/1M; pay for o3 only for coding workflow support.
Decision scorecard
Local evidence first| Signal | Grok-3 | o3 |
|---|---|---|
| Best for | reasoning-heavy apps, multimodal apps, and tool-calling agents | reasoning-heavy apps, multimodal apps, and tool-calling agents |
| Decision fit | Coding, RAG, and Agents | Coding, RAG, and Agents |
| Context window | 131k | 200k |
| Cheapest output | $2.40/1M tokens | $8/1M tokens |
| Provider routes | 4 tracked | 3 tracked |
| Shared benchmarks | 7 shared | Google-Proof Q&A leader |
Decision tradeoffs
- Grok-3 holds a shared-benchmark lead on AIME 2025, ahead by 4.4 points.
- Grok-3 has the lower cheapest tracked output price at $2.40/1M tokens.
- Grok-3 has broader tracked provider coverage for fallback and route flexibility.
- Local decision data tags Grok-3 for Coding, RAG, and Agents.
- o3 holds a shared-benchmark lead on Google-Proof Q&A, ahead by 3.1 points.
- o3 has the larger context window for long prompts, retrieval packs, or transcript analysis.
- o3 uniquely exposes Code execution in local model data.
- Local decision data tags o3 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.
Grok-3
$1,240
Cheapest tracked route/tier: Chutes AI
o3
$3,600
Cheapest tracked route/tier: OpenAI API
Estimated monthly gap: $2,360. 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.
- o3 is $5.60/1M tokens higher on cheapest tracked output pricing, so quality gains need to justify the spend.
- o3 adds Code execution in local capability data.
- Provider overlap exists on OpenRouter; start route-level A/B tests there.
- Grok-3 is $5.60/1M tokens lower on cheapest tracked output pricing before cache, batch, or negotiated discounts.
- Check replacement coverage for Code execution before moving production traffic.
Specs
| Specification | ||
|---|---|---|
| Released | 2025-02-17 | 2025-04-16 |
| Context window | 131k | 200k |
| Parameters | — | — |
| Architecture | - | Decoder Only |
| License | Proprietary | Proprietary |
| Openness | Proprietary | Proprietary |
| Weights | Not released | Not released |
| Code | Unknown | Unknown |
| Commercial use | Commercial use: conditional | Commercial use: conditional |
| Knowledge cutoff | 2025-04 | 2024-06 |
Pricing and availability
| Pricing attribute | Grok-3 | o3 |
|---|---|---|
| Input price | $0.80/1M tokens | $2/1M tokens |
| Output price | $2.40/1M tokens | $8/1M tokens |
| Providers |
Capabilities
| Capability | Grok-3 | o3 |
|---|---|---|
| Vision | Yes | Yes |
| Multimodal | Yes | Yes |
| Reasoning | Yes | Yes |
| JSON / Tool use | Yes | Yes |
| Structured outputs | Yes | Yes |
| Code execution | No | Yes |
| IDE integration | No | No |
| Computer use | No | No |
| Parallel agents | No | No |
Benchmarks
| Benchmark | Grok-3 | o3 |
|---|---|---|
| Google-Proof Q&A | 84.6 | 87.7 |
| AIME 2025 | 93.3 | 88.9 |
| LiveCodeBench | 79.4 | 85.5 |
| Massive Multi-discipline Multimodal Understanding | 78.0 | 82.9 |
| HumanEval | 94.5 | 96.7 |
| Aider Polyglot | 53.3 | 81.3 |
| Chatbot Arena | 1405.0 | 1412.0 |
Continue comparing
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Last reviewed: 2026-07-10. Data sourced from public model cards and provider documentation.