Claude Opus 4.1 vs Grok 4.3 vs o3-pro
Grok 4.3 comes out ahead, 67 to 51 and 49 on our weighted score, and it is the cheaper option too.
AnthropicClaude Opus 4.1
49/100- ECI144.1
- Price$15.00 / $75.00
- Context200K
- Our pick
xAIGrok 4.3
67/100- ECI149.2
- Price$1.25 / $2.50
- Context1M
OpenAIo3-pro
51/100- ECI147.4
- Price$20.00 / $80.00
- Context200K
Grok 4.3 is our pick
Grok 4.3 is the better all-round choice, scoring 67/100 against o3-pro (51) and Claude Opus 4.1 (49). It leads on capability, price, inputs & features and context window. The score weighs capability 50%, price 25%, inputs & features 15%, context window 10%.
- CapabilityGrok 4.3Capabilities Index (ECI): Grok 4.3 149.2 · o3-pro 147.4 · Claude Opus 4.1 144.1
- Lowest priceGrok 4.3Grok 4.3 $1.56 · Claude Opus 4.1 $30.00 · o3-pro $35.00 per 1M tokens (3:1 blend)
- Longest contextGrok 4.3Grok 4.3 1,000,000 · Claude Opus 4.1 200,000 · o3-pro 200,000 tokens
- Widest inputsClaude Opus 4.1 and Grok 4.3Claude Opus 4.1: Text, Images, PDFs · Grok 4.3: Text, Images, PDFs · o3-pro: Text, Images
- Self-hostingNo open weightsAll three are available only through APIs
| Measure | Weight | Claude Opus 4.1 | Grok 4.3 | o3-pro |
|---|---|---|---|---|
| CapabilityCapabilities Index (ECI) | 50% | 71 | 77 | 75 |
| Price | 25% | 0 | 41 | 0 |
| Inputs & features | 15% | 70 | 80 | 70 |
| Context window | 10% | 32 | 60 | 32 |
| Overall | 100% | 49/100 | 67/100 | 51/100 |
Every spec in one table
Highlighted cells lead their row. Dashes mean the data is not published.
| Specification | Claude Opus 4.1Anthropic | Grok 4.3xAI | o3-proOpenAI |
|---|---|---|---|
| Capability | |||
| Capabilities Index (ECI) | 144.1 | 149.2 (best) | 147.4 |
| ECI rank | #81 of 148 | #55 of 148 (best) | #60 of 148 |
| GPQA DiamondGraduate-level science questions | 77.3% | 88.8% (best) | — |
| FrontierMath Tiers 1–3Research-level mathematics | 12.6% | 42.8% (best) | — |
| OTIS Mock AIME 2024–2025Competition mathematics | 68.9% | 93.3% (best) | — |
| SWE-bench VerifiedFixing real GitHub issues | 73.4% | — | — |
| SimpleQA VerifiedShort factual questions | — | 33.2% | — |
| Price per million tokens | |||
| Input | $15.00 | $1.25 (best) | $20.00 |
| Output | $75.00 | $2.50 (best) | $80.00 |
| Cached input | — | $0.20 | — |
| Blended (3:1) | $30.00 | $1.56 (best) | $35.00 |
| Long-context rate | Same rate | Over 200K: $2.50 / $5.00 | Same rate |
| Price source | Median of 14 providers | Official xAI API | Official OpenAI API |
| Limits | |||
| Context window | 200,000 tokens | 1,000,000 tokens (best) | 200,000 tokens |
| Max output | 32,000 tokens | 30,000 tokens | 100,000 tokens (best) |
| Inputs and features | |||
| Text | Yes | Yes | Yes |
| Images | Yes | Yes | Yes |
| PDFs | Yes | Yes | No |
| Audio | No | No | No |
| Video | No | No | No |
| Reasoning | Yes | Yeslow · medium · high | Yeslow · medium · high |
| Tool calling | Yes | Yes | Yes |
| Structured output | No | Yes | Yes |
| Availability | |||
| Weights | Proprietary | Proprietary | Proprietary |
| API model ID | — | grok-4.3 | o3-pro |
| API providers | 14 | 27 (best) | 6 |
| Released | Aug 5, 2025 | Apr 17, 2026 | Jun 10, 2025 |
| Knowledge cutoff | Mar 31, 2025 | — | May 2024 |
What would a month cost?
Enter your expected volume in millions of tokens. List prices only; caching and batch discounts would lower these.
- Claude Opus 4.1$300.00
- Grok 4.3$17.50
- o3-pro$360.00
Which should you choose?
Which is better: Claude Opus 4.1, Grok 4.3 or o3-pro?
Grok 4.3 is the better all-round choice, scoring 67/100 against o3-pro (51) and Claude Opus 4.1 (49). It leads on capability, price, inputs & features and context window. The score weighs capability 50%, price 25%, inputs & features 15%, context window 10%.
Which is cheaper, Claude Opus 4.1, Grok 4.3 or o3-pro?
Grok 4.3 is cheaper at $1.25 input / $2.50 output per million tokens (official xAI API price). Claude Opus 4.1 costs $15.00 input / $75.00 output per million tokens (median across 14 API providers); o3-pro costs $20.00 input / $80.00 output per million tokens (official OpenAI API price). At a typical mix of three input tokens to one output token, that is $1.56 per million tokens for Grok 4.3 versus $30.00 for Claude Opus 4.1 (19× as much) and $35.00 for o3-pro (22× as much).
Which scores higher on benchmarks?
Grok 4.3 scores higher on the Capabilities Index (ECI): Grok 4.3 149.2 (#55 of 148), o3-pro 147.4 (#60 of 148) and Claude Opus 4.1 144.1 (#81 of 148). The confidence ranges of the top two overlap (147.6–150.8 vs 145.8–149.7), so treat the gap as small.
Which is better for coding?
There are no published SWE-bench Verified results for Grok 4.3 and o3-pro yet, so there is no like-for-like coding score. On overall capability, Grok 4.3 leads, which tends to carry over to coding, but test on your own codebase. All three support tool calling for agent workflows.
Which has the bigger context window?
Grok 4.3 has the largest context window at 1,000,000 tokens, against 200,000 for Claude Opus 4.1 and 200,000 for o3-pro. Maximum output per response: Claude Opus 4.1 up to 32,000, Grok 4.3 up to 30,000, o3-pro up to 100,000 tokens.
Which can read images, PDFs, audio or video?
Claude Opus 4.1 accepts text, images and PDFs; Grok 4.3 accepts text, images and PDFs; o3-pro accepts text and images. Claude Opus 4.1 handles the widest range of inputs.
Are any of these open source?
No. Claude Opus 4.1, Grok 4.3 and o3-pro are proprietary and only available through APIs and apps.
Which is newer?
Grok 4.3 is the newest, released Apr 17, 2026. Claude Opus 4.1 came out Aug 5, 2025; o3-pro came out Jun 10, 2025. Knowledge cutoff: Claude Opus 4.1 Mar 31, 2025, o3-pro May 2024.
How do you decide the winner?
Each model gets a 0–100 score on capability (50%, independent benchmark results); price (25%, blended price per million tokens (3 input : 1 output), log scale); inputs & features (15%, image, PDF, audio and video input, tool calling, structured output and reasoning); context window (10%, maximum tokens per request, log scale). Dimensions missing for any model are dropped and the remaining weights rescaled, so every model is judged on the same evidence. Specs and prices come from public model listings and the labs’ own API pages; capability scores come from independent benchmark runs. Data updated Oct 4, 2026.
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