Gemini 4 Argon vs GPT-6 Astra vs Claude Sonnet 5.5
Too close to call on our weighted score (Gemini 4 Argon 74, Claude Sonnet 5.5 72, GPT-6 Astra 68). The right pick depends on what you value most.
GoogleGemini 4 Argon
74/100- ECI166.1
- Price$2.00 / $10.00
- Context1.05M
OpenAIGPT-6 Astra
68/100- ECI169.1
- Price$10.00 / $50.00
- Context1.05M
AnthropicClaude Sonnet 5.5
72/100- ECI166.7
- Price$2.00 / $10.00
- Context1M
Too close to call
It is close. Our weighted score puts them within 3 points (Gemini 4 Argon 74/100, Claude Sonnet 5.5 72/100, GPT-6 Astra 68/100), so choose by what matters most for your work: GPT-6 Astra for raw capability and Gemini 4 Argon on price. The score weighs capability 50%, price 25%, inputs & features 15%, context window 10%.
- CapabilityGPT-6 AstraCapabilities Index (ECI): GPT-6 Astra 169.1 · Claude Sonnet 5.5 166.7 · Gemini 4 Argon 166.1
- Lowest priceGemini 4 Argon and Claude Sonnet 5.5Gemini 4 Argon $4.00 · Claude Sonnet 5.5 $4.00 · GPT-6 Astra $20.00 per 1M tokens (3:1 blend)
- Longest contextGPT-6 Astra and Gemini 4 ArgonGPT-6 Astra 1,050,000 · Gemini 4 Argon 1,048,576 · Claude Sonnet 5.5 1,000,000 tokens
- Widest inputsGemini 4 ArgonGemini 4 Argon: Text, Images, PDFs, Audio, Video · GPT-6 Astra: Text, Images, PDFs · Claude Sonnet 5.5: Text, Images, PDFs
- Self-hostingNo open weightsAll three are available only through APIs
| Measure | Weight | Gemini 4 Argon | GPT-6 Astra | Claude Sonnet 5.5 |
|---|---|---|---|---|
| CapabilityCapabilities Index (ECI) | 50% | 96 | 100 | 97 |
| Price | 25% | 20 | 0 | 20 |
| Inputs & features | 15% | 100 | 80 | 80 |
| Context window | 10% | 61 | 61 | 60 |
| Overall | 100% | 74/100 | 68/100 | 72/100 |
Every spec in one table
Highlighted cells lead their row. Dashes mean the data is not published.
| Specification | Gemini 4 ArgonGoogle | GPT-6 AstraOpenAI | Claude Sonnet 5.5Anthropic |
|---|---|---|---|
| Capability | |||
| Capabilities Index (ECI) | 166.1 | 169.1 (best) | 166.7 |
| ECI rank | #7 of 165 | #1 of 165 (best) | #5 of 165 |
| GPQA DiamondGraduate-level science questions | 96.4% (best) | 95.8% | 95.6% |
| FrontierMath Tiers 1–3Research-level mathematics | 86.0% | 93.7% (best) | 88.8% |
| OTIS Mock AIME 2024–2025Competition mathematics | 100% | 100% | 100% |
| SimpleQA VerifiedShort factual questions | 76.0% (best) | 75.6% | 46.5% |
| Price per million tokens | |||
| Input | $2.00 (best) | $10.00 | $2.00 (best) |
| Output | $10.00 (best) | $50.00 | $10.00 (best) |
| Cached input | $0.10 (best) | $1.00 | $0.10 (best) |
| Blended (3:1) | $4.00 (best) | $20.00 | $4.00 (best) |
| Long-context rate | Same rate | Over 272K: $20.00 / $75.00 | Same rate |
| Price source | Official Google API | Official OpenAI API | Official Anthropic API |
| Limits | |||
| Context window | 1,048,576 tokens | 1,050,000 tokens (best) | 1,000,000 tokens |
| Max output | 65,536 tokens | 128,000 tokens (best) | 128,000 tokens (best) |
| Inputs and features | |||
| Text | Yes | Yes | Yes |
| Images | Yes | Yes | Yes |
| PDFs | Yes | Yes | Yes |
| Audio | Yes | No | No |
| Video | Yes | No | No |
| Reasoning | Yeslow · medium · high | Yeslow · medium · high · xhigh · max | Yeslow · medium · high · xhigh · max |
| Tool calling | Yes | Yes | Yes |
| Structured output | Yes | Yes | Yes |
| Availability | |||
| Weights | Proprietary | Proprietary | Proprietary |
| API model ID | gemini-4-argon | gpt-6-astra | claude-sonnet-5-5 |
| API providers | 24 | 37 (best) | 34 |
| Released | Oct 13, 2026 | Sep 4, 2026 | Sep 28, 2026 |
| Knowledge cutoff | Mar 2026 | Apr 30, 2026 | Jun 2026 |
What would a month cost?
Enter your expected volume in millions of tokens. List prices only; caching and batch discounts would lower these.
- Gemini 4 Argon$40.00
- GPT-6 Astra$200.00
- Claude Sonnet 5.5$40.00
Which should you choose?
Which is better: Gemini 4 Argon, GPT-6 Astra or Claude Sonnet 5.5?
It is close. Our weighted score puts them within 3 points (Gemini 4 Argon 74/100, Claude Sonnet 5.5 72/100, GPT-6 Astra 68/100), so choose by what matters most for your work: GPT-6 Astra for raw capability and Gemini 4 Argon on price. The score weighs capability 50%, price 25%, inputs & features 15%, context window 10%.
Which is cheaper, Gemini 4 Argon, GPT-6 Astra or Claude Sonnet 5.5?
Gemini 4 Argon is cheaper at $2.00 input / $10.00 output per million tokens (official Google API price). Claude Sonnet 5.5 costs $2.00 input / $10.00 output per million tokens (official Anthropic API price); GPT-6 Astra costs $10.00 input / $50.00 output per million tokens (official OpenAI API price). At a typical mix of three input tokens to one output token, that is $4.00 per million tokens for Gemini 4 Argon versus $4.00 for Claude Sonnet 5.5 (1× as much) and $20.00 for GPT-6 Astra (5× as much).
Which scores higher on benchmarks?
GPT-6 Astra scores higher on the Capabilities Index (ECI): GPT-6 Astra 169.1 (#1 of 165), Claude Sonnet 5.5 166.7 (#5 of 165) and Gemini 4 Argon 166.1 (#7 of 165). The confidence ranges of the top two overlap (165.9–174.3 vs 163.6–171.3), so treat the gap as small. On individual benchmarks: GPQA Diamond — Gemini 4 Argon 96.4%, GPT-6 Astra 95.8%, Claude Sonnet 5.5 95.6%; FrontierMath Tiers 1–3 — GPT-6 Astra 93.7%, Claude Sonnet 5.5 88.8%, Gemini 4 Argon 86.0%; OTIS Mock AIME 2024–2025 — Gemini 4 Argon 100%, GPT-6 Astra 100%, Claude Sonnet 5.5 100%; SimpleQA Verified — Gemini 4 Argon 76.0%, GPT-6 Astra 75.6%, Claude Sonnet 5.5 46.5%.
Which is better for coding?
There are no published SWE-bench Verified results for Gemini 4 Argon, GPT-6 Astra and Claude Sonnet 5.5 yet, so there is no like-for-like coding score. On overall capability, GPT-6 Astra 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?
GPT-6 Astra and Gemini 4 Argon have the largest context windows (1,050,000 and 1,048,576 tokens), against 1,000,000 for Claude Sonnet 5.5. Maximum output per response: Gemini 4 Argon up to 65,536, GPT-6 Astra up to 128,000, Claude Sonnet 5.5 up to 128,000 tokens.
Which can read images, PDFs, audio or video?
Gemini 4 Argon accepts text, images, PDFs, audio and video; GPT-6 Astra accepts text, images and PDFs; Claude Sonnet 5.5 accepts text, images and PDFs. Gemini 4 Argon handles the widest range of inputs.
Are any of these open source?
No. Gemini 4 Argon, GPT-6 Astra and Claude Sonnet 5.5 are proprietary and only available through APIs and apps.
Which is newer?
Gemini 4 Argon is the newest, released Oct 13, 2026. Claude Sonnet 5.5 came out Sep 28, 2026; GPT-6 Astra came out Sep 4, 2026. Knowledge cutoff: Gemini 4 Argon Mar 2026, GPT-6 Astra Apr 30, 2026, Claude Sonnet 5.5 Jun 2026.
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 Nov 2, 2026.
