Claude Sonnet 5 vs DeepSeek V4.1 Flash: pricing and benchmarks
DeepSeek V4.1 Flash is 85% cheaper on input tokens ($0.30 vs $2.00 per 1M). DeepSeek V4.1 Flash is 88% cheaper on output tokens ($1.20 vs $10.00 per 1M). On our document Q&A workload (50,000 questions a month), DeepSeek V4.1 Flash costs $156.00 a month versus $1,100 for Claude Sonnet 5, 86% less. Roughly tied. Claude Sonnet 5 scores 156.4 and DeepSeek V4.1 Flash scores 155.6 on the Epoch Capabilities Index, and their confidence intervals overlap.
Prices verified October 29, 2026.
Which should you choose?
Roughly tied. Claude Sonnet 5 scores 156.4 and DeepSeek V4.1 Flash scores 155.6 on the Epoch Capabilities Index, and their confidence intervals overlap.
About even on FrontierMath (Tiers 1–3): 65.6% for Claude Sonnet 5 and 67.4% for DeepSeek V4.1 Flash.
DeepSeek V4.1 Flash costs $0.525 per 1M tokens (3:1 input-to-output mix) vs $4.00 for Claude Sonnet 5, 87% less.
DeepSeek V4.1 Flash delivers statistically similar overall capability for 87% less.
Pricing and specs
| Claude Sonnet 5 | DeepSeek V4.1 Flash | |
|---|---|---|
| Provider | Anthropic | DeepSeek |
| API model ID | claude-sonnet-5 | deepseek-flash |
| Input / 1M tokens | $2.00 | $0.30 |
| Cached input / 1M tokens | $0.20 | $0.006 |
| Output / 1M tokens | $10.00 | $1.20 |
| Long-context rates | — | — |
| Context window | 1M tokens | 1M tokens |
| Max output | 128K tokens | 384K tokens |
| Batch discount | 50% off | — |
Benchmarks
| Claude Sonnet 5 | DeepSeek V4.1 Flash | |
|---|---|---|
| Epoch Capabilities Index | 156.4 | 155.6 |
| GPQA Diamond· Science reasoning | 90.5% | 89.8% |
| FrontierMath (Tiers 1–3)· Advanced math | 65.6% | 67.4% |
| SimpleQA Verified· Factual accuracy | 33.7% | 42.9% |
| ARC-AGI-2· Abstract reasoning | — | 72.9% |
| DeepSWE· Coding | 53.8% | — |
| APEX-Agents· Agentic work | 54.5% | 39.5% |
Source: Epoch AI, best recorded result per model (CC BY 4.0). A dash means no published score. See all benchmarks
Monthly cost for real workloads
| Workload | Claude Sonnet 5 | DeepSeek V4.1 Flash | Difference |
|---|---|---|---|
Support chatbot 100,000 replies a month, ~1,500 input tokens (system prompt + history) and ~400 output tokens each. | $700.00 | $93.00 | DeepSeek V4.1 Flash 87% cheaper |
Document Q&A (RAG) 50,000 questions a month with ~8,000 tokens of retrieved context and ~600 output tokens each. | $1,100 | $156.00 | DeepSeek V4.1 Flash 86% cheaper |
Coding agent 10,000 agent steps a month, ~40,000 input tokens each (70% read from the prompt cache) and ~2,000 output tokens. | $496.00 | $61.68 | DeepSeek V4.1 Flash 88% cheaper |
Estimates use standard list prices and ignore cache-write surcharges. Different tokenizers can count the same text differently, so test with your own prompts.
Claude Sonnet 5 vs DeepSeek V4.1 Flash cost calculator
- $156.00/mo$0.0031 / request
- Claude Sonnet 5Anthropic$1,100/mo$0.02 / request
Standard-tier list prices. Long-context rates apply automatically where the provider publishes a threshold. Excludes cache-write surcharges, taxes, batch and volume discounts.
Claude Sonnet 5 pricing notes
Anthropic’s best combination of speed and intelligence.
- The $2 / $10 launch price is now the standard price; the planned rise to $3 / $15 will not happen.
- Cache writes cost $2.50 (5-minute cache) or $4 (1-hour cache) per 1M tokens.
- Uses Anthropic’s newer tokenizer, which produces roughly 30% more tokens for the same text.
DeepSeek V4.1 Flash pricing notes
DeepSeek’s low-cost model with thinking and non-thinking modes, tool calls and vision input.
- Prices shown are peak rates. Off-peak rates are half: peak hours are 01:00–04:00 and 06:00–10:00 UTC, Monday to Friday.
- Compatible with both OpenAI-format and Anthropic-format APIs.
- Served by model version DeepSeek-V4.1-Flash-1017; the legacy names deepseek-v4-flash and deepseek-v4-flash-vision-exp route to it at the same price.
- Web Search and Fetch cost $0.75 per 1,000 successful requests each; calls made through Claude Code, Codex or DeepSeek Harness are free until November 1, 2026.
Frequently asked questions
- Is Claude Sonnet 5 cheaper than DeepSeek V4.1 Flash?
- DeepSeek V4.1 Flash is 85% cheaper on input tokens ($0.30 vs $2.00 per 1M). DeepSeek V4.1 Flash is 88% cheaper on output tokens ($1.20 vs $10.00 per 1M). On our document Q&A workload (50,000 questions a month), DeepSeek V4.1 Flash costs $156.00 a month versus $1,100 for Claude Sonnet 5, 86% less.
- Which is more capable, Claude Sonnet 5 or DeepSeek V4.1 Flash?
- Roughly tied. Claude Sonnet 5 scores 156.4 and DeepSeek V4.1 Flash scores 155.6 on the Epoch Capabilities Index, and their confidence intervals overlap.
- How much does Claude Sonnet 5 cost per 1M tokens?
- Claude Sonnet 5 costs $2.00 per 1M input tokens and $10.00 per 1M output tokens, and $0.20 per 1M cached input tokens on Anthropic’s standard tier.
- How much does DeepSeek V4.1 Flash cost per 1M tokens?
- DeepSeek V4.1 Flash costs $0.30 per 1M input tokens and $1.20 per 1M output tokens, and $0.006 per 1M cached input tokens on DeepSeek’s standard tier.
- Which has the larger context window, Claude Sonnet 5 or DeepSeek V4.1 Flash?
- Both offer a 1M-token context window.