Claude Sonnet 4.5 vs DeepSeek V4
Benchmarks, API pricing and specs, head to head. Data updated 2026-06-10.
Anthropic · Sep 2025
The model that made 30-hour autonomous coding sessions real — 77.2% SWE-bench Verified and a 1M-token context beta at $3/$15.
DeepSeek · Mar 2026
The open-weights shock of 2026: ~81% SWE-bench Verified, a 1M context and MIT license at $0.30/$0.50 per million tokens.
The verdict
DeepSeek V4 wins 1 of the 1 benchmarks these models share, against 0 for Claude Sonnet 4.5. On price the gap is dramatic: DeepSeek V4 works out roughly 17x cheaper per blended million tokens. DeepSeek V4 also takes 1M of context versus 200K for Claude Sonnet 4.5. And DeepSeek V4 is open-weights (MIT), so it can be self-hosted — a structural advantage if data control or vendor independence matters.
Benchmark head-to-head 0–1
Specs & pricing
| Claude Sonnet 4.5 | DeepSeek V4 | |
|---|---|---|
| modhub Index | 65.5 | — |
| Input price / 1M | $3 | $0.3 |
| Output price / 1M | $15 | $0.5 |
| Context window | 200K | 1M |
| Max output | 64K | 64K |
| Open weights | no | yes (MIT) |
| Reasoning model | yes | yes |
| Multimodal input | text, image | text |
| Knowledge cutoff | Jan 2025 | Dec 2025 |
| Released | Sep 2025 | Mar 2026 |
| Example monthly cost* | $52.50 | $3.75 |
* 10M input + 1.5M output tokens per month at list prices, no caching. Green = better value on that row.
Frequently asked questions
- Which is better, Claude Sonnet 4.5 or DeepSeek V4?
- DeepSeek V4 wins 1 of the 1 benchmarks these models share, against 0 for Claude Sonnet 4.5. On price the gap is dramatic: DeepSeek V4 works out roughly 17x cheaper per blended million tokens. DeepSeek V4 also takes 1M of context versus 200K for Claude Sonnet 4.5. And DeepSeek V4 is open-weights (MIT), so it can be self-hosted — a structural advantage if data control or vendor independence matters.
- Which is cheaper, Claude Sonnet 4.5 or DeepSeek V4?
- Claude Sonnet 4.5 costs $3/$15 per million input/output tokens, while DeepSeek V4 costs $0.3/$0.5. For a typical workload of 10M input and 1.5M output tokens per month, that's $52.50 versus $3.75.
- Which model is better for coding, Claude Sonnet 4.5 or DeepSeek V4?
- On SWE-bench Verified — the standard agentic-coding benchmark — DeepSeek V4 scores ~81% versus 77.2% for Claude Sonnet 4.5, making DeepSeek V4 the stronger pick for coding agents.