DeepSeek vs Claude. Price, context and when to switch.
DeepSeek V4.1-Flash is an MIT-licensed mixture-of-experts with 552B parameters, 8B of them active per prompt token, and image input. Claude Sonnet 5 is Anthropic's closed model. Here is what the same work costs on each.
Side by side.
Claude Sonnet 5 at Anthropic's list price as of October 11, 2026. Open models at OpenRelay's current rates.
| Spec | Claude Sonnet 5 | DeepSeek V4.1-Flash |
|---|---|---|
| Developer | Anthropic | DeepSeek |
| Weights | Closed | Open |
| Context window | 1M | 384K |
| Input | Text, images | Text, images |
| Input / 1M tokens | $2.00 | $0.15 |
| Cached input / 1M | $0.20 | $0.006 |
| Output / 1M tokens | $10.00 | $1.10 |
Monthly cost on common workloads.
100,000 requests a month at realtime rates. Token counts are typical sizes; open any row in the calculator to use your own.
Open the calculator| Workload | Claude Sonnet 5 | DeepSeek V4.1-Flash |
|---|---|---|
| Record matching2,500 in · 150 out | $650.00 | $54.0012x cheaper |
| Classification400 in · 20 out | $100.00 | $8.2012x cheaper |
| Data extraction1,500 in · 300 out | $600.00 | $55.5011x cheaper |
| Support chat3,000 in · 400 out · 50% cached | $730.00 | $67.4011x cheaper |
| RAG answers6,000 in · 500 out · 20% cached | $1,484 | $127.7212x cheaper |
| Agent step20,000 in · 1,500 out · 80% cached | $2,620 | $234.6011x cheaper |
Pick DeepSeek V4.1-Flash for
- High-volume work where the token bill dominates: extraction, classification, matching, summarization.
- Agent loops that read far more than they write: 8B parameters are active per prompt token, 16B per generated one.
- You want the option to self-host later. The weights are MIT-licensed.
Pick Claude Sonnet 5 for
- Prompts over 384K tokens. Sonnet 5 takes 1M; this DeepSeek endpoint serves 384K.
- Tasks where your own evals show Sonnet 5 ahead by enough to pay for the gap.
Questions
Is DeepSeek V4.1-Flash cheaper than Claude Sonnet 5?
Per token, yes. Claude Sonnet 5 lists at $2.00 input and $10.00 output per 1M tokens (as of October 11, 2026). A million record-matching calls a month at 2,500 input and 150 output tokens cost $6,500 on it. DeepSeek V4.1-Flash lists at $0.15 input and $1.10 output per 1M tokens, and runs the same job for $540.00.
Is DeepSeek as good as Claude for coding?
Vendor benchmarks rarely match a specific codebase. Run a sample of your own tasks on both models and compare pass rate and cost per solved task.
Can I call DeepSeek V4.1-Flash with code written for Claude?
Yes. OpenRelay serves it on the Anthropic Messages API as well as chat completions, so the Anthropic SDK works with OpenRelay's base URL, an OpenRelay key and the model id openrelay/deepseek-v4.1-flash.
How should I compare quality?
Take a few hundred real requests where you already know the right answer, run them on both models, and score the outputs the same way. Then divide cost by the share each model gets right. That number, cost per correct answer, is the one to decide on.
Price your own workload.
Your token counts and volume, every model side by side.