Claude Opus 5.5 vs DeepSeek V4.1 Flash 1017
A side-by-side comparison of Claude Opus 5.5 from Anthropic and DeepSeek V4.1 Flash 1017 from DeepSeek, using published pricing, context windows, supported inputs, and release dates.
- Claude Opus 5.5 input
- $4
- DeepSeek V4.1 Flash 1017 input
- $0.3
Key differences
DeepSeek V4.1 Flash 1017 is 93% cheaper on input tokens ($0.3 vs $4 per 1M).
DeepSeek V4.1 Flash 1017 has the larger context window: 1.05M vs 1M tokens.
DeepSeek V4.1 Flash 1017 is the newer release (Oct 17, 2026, vs Sep 22, 2026).
Claude Opus 5.5 vs DeepSeek V4.1 Flash 1017 specs
| Spec | Claude Opus 5.5 | DeepSeek V4.1 Flash 1017 |
|---|---|---|
| Provider | Anthropic | DeepSeek |
| Released | Sep 22, 2026 | Oct 17, 2026 |
| Context window | 1,000,000 tokens | 1,048,576 tokens |
| Input price / 1M tokens | $4 | $0.3 |
| Output price / 1M tokens | $20 | $1.2 |
| 10K in + 1K out request | $0.06 | $0.0042 |
| Accepts | file, image, text | image, text |
| Produces | text | text |
| Tool calling | Yes | Yes |
| Structured outputs | Yes | Yes |
| Reasoning | Yes | Yes |
| Popularity | 47/100 | 65/100 |
Highlighted values are better on that spec: lower price, larger context window, newer release, or higher popularity. Prices in USD per 1M tokens as listed on OpenRouter.
Claude Opus 5.5 vs DeepSeek V4.1 Flash 1017 questions
Is Claude Opus 5.5 or DeepSeek V4.1 Flash 1017 cheaper?
DeepSeek V4.1 Flash 1017 has the lower listed input price ($0.3 per million tokens). For a request with 10,000 input and 1,000 output tokens, Claude Opus 5.5 costs about $0.06 and DeepSeek V4.1 Flash 1017 about $0.0042.
Which has the larger context window?
DeepSeek V4.1 Flash 1017 supports 1,048,576 tokens, the larger of the two.
Which model should I choose?
Pick the cheaper model for high-volume, simpler tasks, and test both on a sample of your real prompts before committing. Price and context size do not measure output quality on your specific workload.