Claude Sonnet 5.5 vs DeepSeek V4 Pro
Claude Sonnet 5.5 comes out ahead, 46 to 39 on our weighted score, though DeepSeek V4 Pro is 2× cheaper per token.
- Our pick
AnthropicClaude Sonnet 5.5
46/100- ECI166.7
- Price$2.00 / $10.00
- Context1M
DeepSeekDeepSeek V4 Pro
39/100- ECI—
- Price$1.60 / $3.30
- Context1M
Add a model
Make it a three-way comparison.
Claude Sonnet 5.5 is our pick
Claude Sonnet 5.5 is the better all-round choice, scoring 46/100 against DeepSeek V4 Pro (39). It leads on inputs & features. DeepSeek V4 Pro 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 priceDeepSeek V4 ProDeepSeek V4 Pro $2.03 · Claude Sonnet 5.5 $4.00 per 1M tokens (3:1 blend)
- Longest contextAbout the sameClaude Sonnet 5.5 1,000,000 · DeepSeek V4 Pro 1,000,000 tokens
- Widest inputsClaude Sonnet 5.5Claude Sonnet 5.5: Text, Images, PDFs · DeepSeek V4 Pro: Text
- Self-hostingDeepSeek V4 ProPublishes downloadable weights
| Measure | Weight | Claude Sonnet 5.5 | DeepSeek V4 Pro |
|---|---|---|---|
| Price | 50% | 20 | 34 |
| Inputs & features | 30% | 80 | 35 |
| Context window | 20% | 60 | 60 |
| Overall | 100% | 46/100 | 39/100 |
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 | DeepSeek V4 ProDeepSeek |
|---|---|---|
| Capability | ||
| Capabilities Index (ECI) | 166.7 | — |
| ECI rank | #5 of 165 | — |
| GPQA DiamondGraduate-level science questions | 95.6% | — |
| FrontierMath Tiers 1–3Research-level mathematics | 88.8% | — |
| OTIS Mock AIME 2024–2025Competition mathematics | 100% | — |
| SimpleQA VerifiedShort factual questions | 46.5% | — |
| Price per million tokens | ||
| Input | $2.00 | $1.60 (best) |
| Output | $10.00 | $3.30 (best) |
| Cached input | $0.10 | — |
| Blended (3:1) | $4.00 | $2.03 (best) |
| Long-context rate | Same rate | Same rate |
| Price source | Official Anthropic API | Median of 56 providers |
| Limits | ||
| Context window | 1,000,000 tokens | 1,000,000 tokens |
| Max output | 128,000 tokens | 384,000 tokens (best) |
| Inputs and features | ||
| Text | Yes | Yes |
| Images | Yes | No |
| PDFs | Yes | No |
| Audio | No | No |
| Video | No | No |
| Reasoning | Yeslow · medium · high · xhigh · max | Yes |
| Tool calling | Yes | Yes |
| Structured output | Yes | No |
| Availability | ||
| Weights | Proprietary | Open |
| API model ID | claude-sonnet-5-5 | — |
| API providers | 34 | 58 (best) |
| Released | Sep 28, 2026 | Apr 24, 2026 |
| Knowledge cutoff | Jun 2026 | May 2025 |
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
- DeepSeek V4 Pro$22.60
Which should you choose?
Which is better: Claude Sonnet 5.5 or DeepSeek V4 Pro?
Claude Sonnet 5.5 is the better all-round choice, scoring 46/100 against DeepSeek V4 Pro (39). It leads on inputs & features. DeepSeek V4 Pro 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 or DeepSeek V4 Pro?
DeepSeek V4 Pro is cheaper at $1.60 input / $3.30 output per million tokens (median across 56 API providers). Claude Sonnet 5.5 costs $2.00 input / $10.00 output per million tokens (official Anthropic API price). At a typical mix of three input tokens to one output token, that is $2.03 per million tokens for DeepSeek V4 Pro versus $4.00 for Claude Sonnet 5.5 (2× as much).
Which scores higher on benchmarks?
There is no independent benchmark that covers both models yet. Claude Sonnet 5.5 has an ECI of 166.7 and DeepSeek V4 Pro has not been scored yet.
Which is better for coding?
There are no published SWE-bench Verified results for Claude Sonnet 5.5 and DeepSeek V4 Pro yet, so there is no like-for-like coding score. Test both on a sample of your own tasks. Both support tool calling for agent workflows.
Which has the bigger context window?
Claude Sonnet 5.5 and DeepSeek V4 Pro share the same 1,000,000-token context window. Maximum output per response: Claude Sonnet 5.5 up to 128,000, DeepSeek V4 Pro up to 384,000 tokens.
Which can read images, PDFs, audio or video?
Claude Sonnet 5.5 accepts text, images and PDFs; DeepSeek V4 Pro accepts text. Claude Sonnet 5.5 handles the widest range of inputs.
Are any of these open source?
DeepSeek V4 Pro publishes its weights and can be self-hosted; Claude Sonnet 5.5 is proprietary.
Which is newer?
Claude Sonnet 5.5 is the newest, released Sep 28, 2026. DeepSeek V4 Pro came out Apr 24, 2026. Knowledge cutoff: Claude Sonnet 5.5 Jun 2026, DeepSeek V4 Pro May 2025.
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.
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