Claude Sonnet 5.5 vs GPT-5 Chat vs Gemini 4 Argon
Gemini 4 Argon comes out ahead, 52 to 46 and 31 on our weighted score, though GPT-5 Chat is 14% cheaper per token.
AnthropicClaude Sonnet 5.5
46/100- ECI166.7
- Price$2.00 / $10.00
- Context1M
OpenAIGPT-5 Chat
31/100- ECI—
- Price$1.25 / $10.00
- Context400K
- Our pick
GoogleGemini 4 Argon
52/100- ECI166.1
- Price$2.00 / $10.00
- Context1.05M
Gemini 4 Argon is our pick
Gemini 4 Argon is the better all-round choice, scoring 52/100 against Claude Sonnet 5.5 (46) and GPT-5 Chat (31). It leads on inputs & features. GPT-5 Chat wins on price. The score weighs price 50%, inputs & features 30%, context window 20%. None of the shared benchmarks cover every model here yet, so capability is left out of this verdict.
- CapabilityNot enough dataNo independent benchmark covers every model here yet
- Lowest priceGPT-5 ChatGPT-5 Chat $3.44 · Claude Sonnet 5.5 $4.00 · Gemini 4 Argon $4.00 per 1M tokens (3:1 blend)
- Longest contextGemini 4 ArgonGemini 4 Argon 1,048,576 · Claude Sonnet 5.5 1,000,000 · GPT-5 Chat 400,000 tokens
- Widest inputsGemini 4 ArgonClaude Sonnet 5.5: Text, Images, PDFs · GPT-5 Chat: Text, Images · Gemini 4 Argon: Text, Images, PDFs, Audio, Video
- Self-hostingNo open weightsAll three are available only through APIs
| Measure | Weight | Claude Sonnet 5.5 | GPT-5 Chat | Gemini 4 Argon |
|---|---|---|---|---|
| Price | 50% | 20 | 23 | 20 |
| Inputs & features | 30% | 80 | 35 | 100 |
| Context window | 20% | 60 | 44 | 61 |
| Overall | 100% | 46/100 | 31/100 | 52/100 |
Left out because at least one model lacks the data: capability. The remaining weights were rescaled.
Every spec in one table
Highlighted cells lead their row. Dashes mean the data is not published.
| Specification | Claude Sonnet 5.5Anthropic | GPT-5 ChatOpenAI | Gemini 4 ArgonGoogle |
|---|---|---|---|
| Capability | |||
| Capabilities Index (ECI) | 166.7 (best) | — | 166.1 |
| ECI rank | #5 of 165 (best) | — | #7 of 165 |
| GPQA DiamondGraduate-level science questions | 95.6% | — | 96.4% (best) |
| FrontierMath Tiers 1–3Research-level mathematics | 88.8% (best) | — | 86.0% |
| OTIS Mock AIME 2024–2025Competition mathematics | 100% | — | 100% |
| SimpleQA VerifiedShort factual questions | 46.5% | — | 76.0% (best) |
| Price per million tokens | |||
| Input | $2.00 | $1.25 (best) | $2.00 |
| Output | $10.00 | $10.00 | $10.00 |
| Cached input | $0.10 | — | $0.10 |
| Blended (3:1) | $4.00 | $3.44 (best) | $4.00 |
| Long-context rate | Same rate | Same rate | Same rate |
| Price source | Official Anthropic API | Median of 5 providers | Official Google API |
| Limits | |||
| Context window | 1,000,000 tokens | 400,000 tokens | 1,048,576 tokens (best) |
| Max output | 128,000 tokens (best) | 128,000 tokens (best) | 65,536 tokens |
| Inputs and features | |||
| Text | Yes | Yes | Yes |
| Images | Yes | Yes | Yes |
| PDFs | Yes | No | Yes |
| Audio | No | No | Yes |
| Video | No | No | Yes |
| Reasoning | Yeslow · medium · high · xhigh · max | Yes | Yeslow · medium · high |
| Tool calling | Yes | No | Yes |
| Structured output | Yes | No | Yes |
| Availability | |||
| Weights | Proprietary | Proprietary | Proprietary |
| API model ID | claude-sonnet-5-5 | — | gemini-4-argon |
| API providers | 34 (best) | 5 | 24 |
| Released | Sep 28, 2026 | Aug 7, 2025 | Oct 13, 2026 |
| Knowledge cutoff | Jun 2026 | Sep 30, 2024 | Mar 2026 |
What would a month cost?
Enter your expected volume in millions of tokens. List prices only; caching and batch discounts would lower these.
- Claude Sonnet 5.5$40.00
- GPT-5 Chat$32.50
- Gemini 4 Argon$40.00
Which should you choose?
Which is better: Claude Sonnet 5.5, GPT-5 Chat or Gemini 4 Argon?
Gemini 4 Argon is the better all-round choice, scoring 52/100 against Claude Sonnet 5.5 (46) and GPT-5 Chat (31). It leads on inputs & features. GPT-5 Chat wins on price. The score weighs price 50%, inputs & features 30%, context window 20%. None of the shared benchmarks cover every model here yet, so capability is left out of this verdict.
Which is cheaper, Claude Sonnet 5.5, GPT-5 Chat or Gemini 4 Argon?
GPT-5 Chat is cheaper at $1.25 input / $10.00 output per million tokens (median across 5 API providers). Claude Sonnet 5.5 costs $2.00 input / $10.00 output per million tokens (official Anthropic API price); Gemini 4 Argon costs $2.00 input / $10.00 output per million tokens (official Google API price). At a typical mix of three input tokens to one output token, that is $3.44 per million tokens for GPT-5 Chat versus $4.00 for Claude Sonnet 5.5 (1.2× as much) and $4.00 for Gemini 4 Argon (1.2× as much).
Which scores higher on benchmarks?
There is no independent benchmark that covers all three models yet. Claude Sonnet 5.5 has an ECI of 166.7, GPT-5 Chat has not been scored yet and Gemini 4 Argon has an ECI of 166.1.
Which is better for coding?
There are no published SWE-bench Verified results for Claude Sonnet 5.5, GPT-5 Chat and Gemini 4 Argon yet, so there is no like-for-like coding score. Test both on a sample of your own tasks. Note that GPT-5 Chat does not support tool calling, which most coding agents need.
Which has the bigger context window?
Gemini 4 Argon has the largest context window at 1,048,576 tokens, against 1,000,000 for Claude Sonnet 5.5 and 400,000 for GPT-5 Chat. Maximum output per response: Claude Sonnet 5.5 up to 128,000, GPT-5 Chat up to 128,000, Gemini 4 Argon up to 65,536 tokens.
Which can read images, PDFs, audio or video?
Claude Sonnet 5.5 accepts text, images and PDFs; GPT-5 Chat accepts text and images; Gemini 4 Argon accepts text, images, PDFs, audio and video. Gemini 4 Argon handles the widest range of inputs.
Are any of these open source?
No. Claude Sonnet 5.5, GPT-5 Chat and Gemini 4 Argon 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-5 Chat came out Aug 7, 2025. Knowledge cutoff: Claude Sonnet 5.5 Jun 2026, GPT-5 Chat Sep 30, 2024, Gemini 4 Argon Mar 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.
