Claude Sonnet 4.5 vs DeepSeek V4.1 Flash
At a Glance
| Compare | Claude Sonnet 4.5Anthropic |  DeepSeek V4.1 FlashDeepSeek |
|---|---|---|
| Intelligence, Cost, and Efficiency | ||
| IntelligenceHigher is better · MM Intelligence v2.5 | #36 of 4627.7 score · 2/3 sources · provisional · missing LiveBench · full-core range 18.5–51.8 | UnrankedNot in the 46-model eligible cohort |
| CostLower is better · Published-token output estimate | UnrankedNot in the 44-model eligible cohort | #5 of 44$0.022 per LiveBench case |
| Pricing and Limits | ||
| Input priceFrom · USD / 1M tokens | $3.00Anthropic ↗ · Sep 3, 2026 | $0.15DeepSeek ↗ · Sep 10, 2026 |
| Output priceFrom · USD / 1M tokens | $15.00Anthropic ↗ · Sep 3, 2026 | $0.60Deepinfra ↗ · Sep 22, 2026 |
| Context windowMaximum documented tokens | 200K | 1,049K |
| Model facts checked | Sep 3, 2026View model evidence → | Sep 10, 2026View model evidence → |
Token prices are the lowest available sourced USD rates; input and output may use different providers. Cost ranking estimates output spend on LiveBench, not a full request bill. Ranking methodology →
Available Benchmarks
| Benchmark | Claude Sonnet 4.5 | DeepSeek-V4.1-Flash |
|---|---|---|
| ToneBench2026-09-11-10-task-4ef099199c9c · overall_score · unverified | 77.2588% of row best · points · Claude Sonnet 4.5 · 7,415 output tokens / case | 88.03100% of row best · points · DeepSeek V4.1 Flash (max) · 18,199 output tokens / case |
| Overall ResultCounted from the protocol-matched rows above | 0 benchmark winsNo overall winner | 0 benchmark winsNo overall winner |
Third-party benchmark Only like-for-like primary-publisher results are shown; raw scores, relative scores, configuration, and token spend remain visible.
Side-by-Side Facts
| Field | Claude Sonnet 4.5 | DeepSeek-V4.1-Flash |
|---|---|---|
| Developer | Anthropic | DeepSeek |
| Family | Claude 4 | Deepseek V4 1 |
| Model | Claude Sonnet 4.5 | DeepSeek-V4.1-Flash |
| Version | Claude Sonnet 4.5 | DeepSeek-V4.1-Flash |
| Lifecycle | active | active |
| Released | 2025-09-29 | 2026-09-10 |
| Knowledge cutoff | 2025-01-01 | Unknown |
| Input modalities | Text, Image | Text, Image |
| Output modalities | Text | Text |
| Context window | 200K | 1,049K |
| Total parameters | Unknown | 763.2B |
| Active parameters | Unknown | Unknown |
| License | Unknown | mit |
| Open weights | No | Yes |
| API available | Yes | Yes |
| Self-hostable | No | Yes |
| Provider access | Anthropic (Standard) | DeepSeek (Standard), Deepinfra (Standard), Together Ai (Standard) |
| Capabilities | chat, generation, reasoning, structured_outputs, tools | agents, chat, fim, generation, reasoning, responses, structured_outputs, tools, vision |
| Architecture design | Unknown | Causal Encoder-Decoder (20 encoder + 20 decoder layers) |
| Backbone parameters | Unknown | 552000000000 parameters |
| Active parameters during decode | Unknown | 16000000000 parameters |
| Active parameters during prefill | Unknown | 8000000000 parameters |
| Pre-training corpus | Unknown | 45000000000000 tokens |
| Reasoning effort range | Unknown | 1–100 |
| Routed experts per MoE layer | Unknown | 384 experts |
| Routed experts per token | Unknown | 6 experts |
| Transformer layers | Unknown | 40 layers |
Claude Sonnet 4.5 Capabilities
DeepSeek V4.1 Flash Capabilities
Related Comparisons
All image comparisons →| A | Pair | B | Context |
|---|---|---|---|
Claude Sonnet 4.5Anthropic | vs | DeepSeek-V4-FlashDeepSeek | cross-developer peerstext |
Claude Sonnet 4.5Anthropic | vs |  GPT-6 AstraOpenAI | cross-developer peersimage, text |
Claude Fable 5.1Anthropic | vs | Claude Sonnet 4.5Anthropic | family variantsimage, text |
Claude Sonnet 4.5Anthropic | vs |  Gemini 3.1 ProGoogle DeepMind | cross-developer peerstext |
Claude Sonnet 4.5Anthropic | vs | Grok 4.6xAI | cross-developer peersimage, text |
Claude Sonnet 4.5Anthropic | vs |  Qwen3.8-MaxQwen | cross-developer peersimage, text |
Claude Sonnet 4.5Anthropic | vs |  Kimi-K3Moonshot AI | cross-developer peersimage, text |
 MiniMax-M3MiniMax | vs | Claude Sonnet 4.5Anthropic | cross-developer peersimage, text |
Claude Sonnet 4.5Anthropic | vs |  GLM-5.3Z.ai | cross-developer peerstext |
Claude Sonnet 4.5Anthropic | vs |  Hy4 previewTencent | cross-developer peerstext |
Claude Sonnet 4.5Anthropic | vs | Seed 2.1 ProByteDance Seed | cross-developer peersimage, text |
Claude Sonnet 4.5Anthropic | vs |  Mistral Large 3Mistral AI | cross-developer peersimage, text |
Primary Evidence
Sources and Freshness
Questions
Claude Sonnet 4.5 vs DeepSeek V4.1 Flash FAQs
Is Claude Sonnet 4.5 or DeepSeek V4.1 Flash better for coding?+
This comparison does not currently contain a protocol-matched coding benchmark for both Claude Sonnet 4.5 and DeepSeek V4.1 Flash, so Model Markets cannot name a coding leader from pricing, context size, or capability labels alone.
Which is cheaper, Claude Sonnet 4.5 or DeepSeek V4.1 Flash?+
Claude Sonnet 4.5 is $3.00 and DeepSeek V4.1 Flash is $0.15 per million tokens, so DeepSeek V4.1 Flash is cheaper on this metric. Claude Sonnet 4.5 is $15.00 and DeepSeek V4.1 Flash is $0.60 per million tokens, so DeepSeek V4.1 Flash is cheaper on this metric.
Which has a larger context window, Claude Sonnet 4.5 or DeepSeek V4.1 Flash?+
DeepSeek V4.1 Flash has the larger sourced context window. Claude Sonnet 4.5 supports 200K and DeepSeek V4.1 Flash supports 1,049K.
Which performs better in benchmarks, Claude Sonnet 4.5 or DeepSeek V4.1 Flash?+
There is no overall benchmark winner: At least two independently verified, protocol-matched benchmarks are required for an overall winner.
Can Claude Sonnet 4.5 or DeepSeek V4.1 Flash be self-hosted?+
DeepSeek V4.1 Flash is the only model in this pair currently marked as self-hostable. Claude Sonnet 4.5 is not marked open weight; DeepSeek V4.1 Flash is open weight.
Can Claude Sonnet 4.5 and DeepSeek V4.1 Flash understand images?+
Claude Sonnet 4.5 is documented with image input; DeepSeek V4.1 Flash is documented with image input. This reflects supported input modalities, not vision quality.
Which can generate longer answers, Claude Sonnet 4.5 or DeepSeek V4.1 Flash?+
DeepSeek V4.1 Flash has the larger sourced maximum output: Claude Sonnet 4.5 supports 64K and DeepSeek V4.1 Flash supports 393K output tokens.
Do Claude Sonnet 4.5 and DeepSeek V4.1 Flash support reasoning and tool use?+
Claude Sonnet 4.5: reasoning, tool calling, and image input. DeepSeek V4.1 Flash: reasoning, tool calling, and image input. Feature support does not establish relative quality.
Which is available from more inference providers, Claude Sonnet 4.5 or DeepSeek V4.1 Flash?+
Claude Sonnet 4.5 has 1 sourced provider route; DeepSeek V4.1 Flash has 3, so DeepSeek V4.1 Flash has broader tracked availability.
Which offers better value, Claude Sonnet 4.5 or DeepSeek V4.1 Flash?+
There is no universal value winner. Compare the input and output prices above with the matched benchmark result for your workload: cheaper tokens can be offset by different quality, token usage, latency, or provider availability.