AI model comparison
Claude Opus 5.5 vs DeepSeek V4.1 Flash
Pricing, context window, benchmarks, and features compared side by side. Or skip the guesswork and send one prompt to both.
Anthropic
Claude Opus 5.5
Claude Opus 5.5 is Anthropic's flagship model for demanding reasoning, coding, and long-horizon agentic work, succeeding Claude Opus 5.
- Input / 1M
- $4
- Output / 1M
- $20
- Context
- 1M
DeepSeek
DeepSeek V4.1 Flash
DeepSeek V4.1 Flash is a sparse mixture-of-experts model from DeepSeek, and the first built on the company's Causal Encoder-Decoder (CED) architecture.
- Input / 1M
- $0.30
- Output / 1M
- $1.20
- Context
- 1.05M
At a glance
Quick verdict
How the two models stack up on the things people ask about most.
Lower price
DeepSeek V4.1 Flash
15.0x cheaper for a typical chat
Higher intelligence score
Claude Opus 5.5
57.6 vs 39.5 on Artificial Analysis
Larger context window
DeepSeek V4.1 Flash
1.05M vs 1M tokens
Newer release
Claude Opus 5.5
Released September 22, 2026
Benchmarks
Benchmark scores
Independent scores from Artificial Analysis. Higher is better.
Intelligence index
Claude Opus 5.557.6DeepSeek V4.1 Flash39.5Coding index
Claude Opus 5.5Not availableDeepSeek V4.1 FlashNot availableAgentic index
Claude Opus 5.5Not availableDeepSeek V4.1 FlashNot availablePricing
Claude Opus 5.5 vs DeepSeek V4.1 Flash API pricing
Per-token API rates. Cheaper option highlighted.
| Metric | Claude Opus 5.5 | DeepSeek V4.1 Flash |
|---|---|---|
| Input tokensPer 1M tokens | $4 | $0.30 |
| Output tokensPer 1M tokens | $20 | $1.20 |
| Cached input (read)Per 1M tokens | $0.20 | $0.01 |
| Cache writePer 1M tokens | $5 | Not available |
| Web searchPer request | $0.01 | Not available |
What it costs in practice
Estimated cost per 1,000 requests at standard rates. Coding and long-document figures also show the cost when the input is already cached.
Chat message
2K in, 500 out
Claude Opus 5.5$18DeepSeek V4.1 Flash$1.20Coding task
30K in, 4K out
Claude Opus 5.5$200$86 cachedDeepSeek V4.1 Flash$13.80$4.98 cachedLong document summary
150K in, 2K out
Claude Opus 5.5$640$70 cachedDeepSeek V4.1 Flash$47.40$3.30 cachedSpecs
Context window and capabilities
How much each model can read, how much it can write, and what it accepts as input.
| Metric | Claude Opus 5.5 | DeepSeek V4.1 Flash |
|---|---|---|
| Context window | 1M tokens | 1.05M tokens |
| Max output | 128K tokens | 944K tokens |
| Input types | File, Image, Text | Image, Text |
| Output types | Text | Text |
| Reasoning effort levels | Max, Extra high, High, Medium, Low | Max, High, Low |
| Default reasoning effort | High | High |
| Release date | September 22, 2026 | September 10, 2026 |
Features
Supported features
API features available for each model.
| Metric | Claude Opus 5.5 | DeepSeek V4.1 Flash |
|---|---|---|
| Tool calling | Supported | Supported |
| Structured outputs | Supported | Supported |
| JSON mode | Supported | Supported |
| Reasoning | Supported | Supported |
| Temperature | Not supported | Supported |
| Stop sequences | Supported | Supported |
| Deterministic seed | Not supported | Supported |
| Verbosity control | Supported | Not supported |
Keep exploring
More on these models
Other head-to-heads, the full model page, and the alternatives list for each model.
Claude Opus 5.5View full model details- Claude Opus 5.5 vs Claude Sonnet 5.5
- Claude Opus 5.5 vs Claude Fable 5.1
- Claude Opus 5.5 vs GPT-6 Astra
- Claude Opus 5.5 vs GPT-6.1 Sol
- Claude Opus 5.5 vs Claude Opus 5
- Claude Opus 5.5 vs Claude Fable 5
- Claude Opus 5.5 vs Muse Spark 1.3
- Claude Opus 5.5 vs GLM 5.3 Flash
- Claude Opus 5.5 vs GPT-6 Sol
- Claude Opus 5.5 vs MiMo-V2.6-Flash
- Claude Opus 5.5 vs GPT-5.6 Sol
- Claude Opus 5.5 vs Hy4 preview
- Claude Opus 5.5 vs Grok 4.7
- Claude Opus 5.5 vs GPT-6 Luna
- Claude Opus 5.5 vs DeepSeek V4 Flash 0731
- Claude Opus 5.5 vs GLM 5.3
- Claude Opus 5.5 vs Kimi K3
- Claude Opus 5.5 vs DeepSeek V4 Flash 0423
- Claude Opus 5.5 vs Step 5 Preview
- Claude Opus 5.5 vs Gemini 3.8 Flash
- Claude Opus 5.5 vs Hy3
- Claude Opus 5.5 vs Gemini 3.1 Pro Preview
DeepSeek V4.1 FlashView full model details- DeepSeek V4.1 Flash vs GLM 5.3 Flash
- DeepSeek V4.1 Flash vs MiMo-V2.6-Flash
- DeepSeek V4.1 Flash vs Hy4 preview
- DeepSeek V4.1 Flash vs GPT-6 Luna
- DeepSeek V4.1 Flash vs DeepSeek V4 Flash 0731
- DeepSeek V4.1 Flash vs GLM 5.3
- DeepSeek V4.1 Flash vs DeepSeek V4 Flash 0423
- DeepSeek V4.1 Flash vs Step 5 Preview
- DeepSeek V4.1 Flash vs Gemini 3.8 Flash
- DeepSeek V4.1 Flash vs Hy3
- DeepSeek V4.1 Flash vs GPT-5.6 Luna
- DeepSeek V4.1 Flash vs GPT-6.1 Sol
- DeepSeek V4.1 Flash vs Muse Spark 1.3 Contributor
- DeepSeek V4.1 Flash vs GLM 5.2
- DeepSeek V4.1 Flash vs Claude Sonnet 5.5
- DeepSeek V4.1 Flash vs MiMo-V2.6-Pro
- DeepSeek V4.1 Flash vs MiniMax M3
- DeepSeek V4.1 Flash vs DeepSeek V4 Pro 0813
- DeepSeek V4.1 Flash vs GPT-6 Astra
- DeepSeek V4.1 Flash vs Claude Opus 5
- DeepSeek V4.1 Flash vs Claude Fable 5.1
- DeepSeek V4.1 Flash vs Claude Sonnet 5
- DeepSeek V4.1 Flash vs DeepSeek V4 Pro 0423
- DeepSeek V4.1 Flash vs Muse Spark 1.3
- DeepSeek V4.1 Flash vs GPT-6 Luna Pro
- DeepSeek V4.1 Flash vs Qwen3.8 Max (0902)
- DeepSeek V4.1 Flash vs Claude Haiku 5.5
- DeepSeek V4.1 Flash vs Qwen3.8 27B
- DeepSeek V4.1 Flash vs Grok 4.6
- DeepSeek V4.1 Flash vs Ling 3.1 Flash
- DeepSeek V4.1 Flash vs GPT-5.6 Terra
- DeepSeek V4.1 Flash vs Claude Opus 4.8
- DeepSeek V4.1 Flash vs Qwen3.8 Flash
- DeepSeek V4.1 Flash vs Gemini 3.7 Flash
- DeepSeek V4.1 Flash vs Qwen3.7 Flash
- DeepSeek V4.1 Flash vs Claude Opus 4.7
- DeepSeek V4.1 Flash vs Qwen3.8 2.4T A95B
- DeepSeek V4.1 Flash vs Muse Spark 1.2
- DeepSeek V4.1 Flash vs GPT-5.4
- DeepSeek V4.1 Flash vs Grok 4.5
- DeepSeek V4.1 Flash vs GPT-5.5
- DeepSeek V4.1 Flash vs DeepSeek V4 Flash Vision Exp
- DeepSeek V4.1 Flash vs GLM 5.3 FlashX
- DeepSeek V4.1 Flash vs Gemini 3.6 Flash
- DeepSeek V4.1 Flash vs Muse Spark 1.1
- DeepSeek V4.1 Flash vs GPT-5.6 Luna Pro
Our take
Opus 5.5 is in a different quality tier (57.6 vs 39.5). Use DeepSeek V4.1 Flash when cost and throughput matter more than peak reasoning, and keep Opus for the work you would have given a flagship last year.
FAQ
Frequently asked questions
Is Claude Opus 5.5 or DeepSeek V4.1 Flash cheaper?
DeepSeek V4.1 Flash is cheaper for a typical chat (2K input tokens and 500 output tokens). DeepSeek V4.1 Flash costs $0.30 per 1M input tokens and $1.20 per 1M output tokens, while Claude Opus 5.5 costs $4 per 1M input tokens and $20 per 1M output tokens.
Which has a bigger context window, Claude Opus 5.5 or DeepSeek V4.1 Flash?
DeepSeek V4.1 Flash supports up to 1.05M tokens of context, compared with 1M for Claude Opus 5.5.
Is Claude Opus 5.5 smarter than DeepSeek V4.1 Flash?
On the Artificial Analysis Intelligence Index, Claude Opus 5.5 scores 57.6 and DeepSeek V4.1 Flash scores 39.5, putting Claude Opus 5.5 ahead. Benchmarks don't capture everything, so the best test is running your own prompts through both.
Can I use Claude Opus 5.5 and DeepSeek V4.1 Flash at the same time?
Yes. Shortcut Chat sends one prompt to multiple models at once, so you can see Claude Opus 5.5 and DeepSeek V4.1 Flash answer side by side and keep the better response.
Why choose? Ask both.
Send one prompt to Claude Opus 5.5 and DeepSeek V4.1 Flash at the same time. Compare the answers side by side and keep the best one.