Head-to-Head Model Comparison

DeepSeek V4.1-Flash vs Claude Opus 5.5

Benchmarks, API Token Pricing, Context Window & Speed Comparison

Reviewed by the GetInfoUs research teamLast reviewed: October 2026Editorial policy
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DeepSeekAnthropicopen-sourceflagship

Compare DeepSeek V4.1-Flash by DeepSeek against Claude Opus 5.5 by Anthropic across real-world coding, reasoning, token economics, and latency.

Head-to-Head Comparison

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DeepSeek

DeepSeek V4.1-Flash

KV-Cache Killer

763B total / 16B active causal encoder-decoder MoE with 1/4 KV-cache usage, native vision, MIT license, and world-record low off-peak pricing.

Intelligence Index58 / 100
Input Token:

$0.30 / 1M

Output Token:

$1.20 / 1M

Context Window:

1M tokens

SWE-bench Verified:

74.2%

Anthropic

Claude Opus 5.5

Frontier Intelligence Titan

Anthropic's most intelligent model for complex reasoning, research, and strategic analysis.

Intelligence Index94 / 100
Input Token:

$4.00 / 1M

Output Token:

$20.00 / 1M

Context Window:

1M tokens

SWE-bench Verified:

84.6%

Key Differences at a Glance

  • DeepSeek V4.1-Flash is 16.0x cheaper for API usage (input + output tokens combined).
  • DeepSeek V4.1-Flash is faster at 110 tok/s vs 78 tok/s.
  • Claude Opus 5.5 leads on SWE-bench coding (84.6% vs 74.2%).
Need definitions for token pricing, context, or benchmarks?Explore AI Glossary →
FeatureDeepSeek V4.1-FlashClaude Opus 5.5
Intelligence Index
Composite reasoning & knowledge score (0-100)
5894
Provider
DeepSeekAnthropic
Input Price
Cost per million input tokens
$0.30 / 1M$4.00 / 1M
Output Price
Cost per million output tokens
$1.20 / 1M$20.00 / 1M
Blended Price
Weighted 7:2:1 cache:input:output per 1M
$0.18 / 1M$3.08 / 1M
Context Window
Maximum input + output tokens
1M tokens~1,500 A4 pages of text1M tokens~1,500 A4 pages of text
Max Output Tokens
Per single request
384K128K
Throughput Speed
Tokens generated per second
110 tok/s78 tok/s
SWE-bench Verified
Real-world software engineering
74.2%84.6%
GPQA Diamond
Graduate-level reasoning
90.9%82.3%
Cached Input Price
Prompt caching discount per 1M tokens
$0.01 / 1M$0.40 / 1M

Who Wins Where?

At-a-glance decision framework
Coding
Claude Opus 5.5
+10.4% SWE-bench lead
Cost
DeepSeek V4.1-Flash
16.0x cheaper monthly runtime
Speed
DeepSeek V4.1-Flash
+41% faster generation
Context
Tied
1M tokens window

Empirical Head-to-Head Benchmark Scores

Official evaluation metrics verified by independent third-party research labs.

DeepSeek V4.1-FlashClaude Opus 5.5
SWE-bench Verified (Autonomous Coding)

Industry benchmark evaluating real-world GitHub issue resolution and multi-file debugging.

74.2%vs84.6%
GPQA Diamond (Doctorate-Level Science & Math)

Challenging questions created by domain experts to test complex PhD-level reasoning.

90.9%vs82.3%
MMLU-Pro (Multi-task Language Understanding)

Hardened reasoning and academic knowledge benchmark with reduced lucky-guess probability.

89.5%vs91.5%
LMSYS Chatbot Arena Elo

Crowdsourced human preference evaluation based on blind, head-to-head model battles.

1455ptsvs1507pts
Humanity's Last Exam (Frontier Expert Knowledge)

Extremely difficult, closed-ended questions spanning the frontier of human expert knowledge.

16.8%vs19.8%
Terminal-Bench (Agentic Coding & Terminal Use)

Autonomous multi-step tasks executed inside a real command-line terminal environment.

31.2%vs66.4%
SciCode (Scientific Computing)

Research-grade coding problems drawn from real scientific and numerical workloads.

48%vs58.7%
LiveCodeBench (Competitive Coding)

Contamination-free competitive programming problems collected continuously over time.

73%vs83.1%
AIME (Advanced Math Competition)

American Invitational Mathematics Examination — multi-step Olympiad-level reasoning.

92.4%vs95.4%
Long-Context Reasoning

Accuracy when reasoning over very large inputs that fill the model context window.

93%vs92.6%
Generation Speed (Throughput)

Tokens emitted per second during active generation streaming.

110 tok/s vs78 tok/s

Latency & Response Time

Time to first token (TTFT) and estimated end-to-end response time for a typical 500-token response.

Time to First Token (TTFT)Lower is better
DeepSeek V4.1-Flash0.46s
Claude Opus 5.51.40s
Est. End-to-End Response (500 tokens)TTFT + generation time
DeepSeek V4.1-Flash5.01s
Claude Opus 5.57.81s

Real-Time Interactive Token Cost Simulator

Adjust sliders to calculate projected monthly cloud API spending with prompt caching discounts.

100K / day
10K500K1M
30K / day
5K150K300K
50% cached
0% (Cold)50%90% (Warm)
DeepSeek V4.1-Flash Monthly API Bill
$1.54 / month
$0.3/1M in · $1.2/1M out
Claude Opus 5.5 Monthly API Bill
$24.60 / month
$4/1M in · $20/1M out
DeepSeek V4.1-Flash saves approximately $23.06 / month (94%) under this workload.16.0x Savings

DeepSeek V4.1-Flash · Strengths & Key Advantages

  • MIT permissive open license with full weights, architecture, and code
  • Revolutionary causal encoder-decoder architecture: KV cache only 890 bytes/token (runs on commodity NVMe SSDs)
  • World's lowest pricing: off-peak cached input at just $0.003/1M and $0.27 cost per benchmark task
  • Colossal 1M context input paired with 384,000 maximum output tokens and native vision
Considerations & Trade-offs
  • Extremely verbose generation (averages 8.9K output tokens per inquiry without explicit caps)
  • Long-horizon performance degrades on Terminal-Bench 4.0 (31.2%)
  • Factual knowledge recall dips on SimpleQA (42.3) and vision resolution is capped at 672x672

Claude Opus 5.5 · Strengths & Key Advantages

  • Unmatched autonomous multi-step agentic coding and refactoring
  • Flawless multi-document reasoning over 1M token context with no long-prompt surcharge
  • Highest composite Intelligence Index score measured (94/100), leading SWE-bench Verified at 84.6%
  • Precise tool execution with robust error-recovery loops
Considerations & Trade-offs
  • Premium output pricing ($20.00/M) plus heavy reasoning-token usage (~68K output tokens per complex task) keeps long agentic runs expensive
  • Long thinking times at maximum effort can push a single hard agentic task toward ~$3.85+

Token Use & Task Economics

Estimated cost and token consumption to complete one representative agentic task.

MetricDeepSeek V4.1-FlashClaude Opus 5.5
Cost per Task
Estimated USD to finish one task
$0.27$3.85
Output Tokens / Task
Tokens generated per task
58K68K
Reasoning Tokens / Task
Thinking tokens burned per task
28K42K

Technical Specifications

Architecture, release timeline, capabilities, and modalities.

FeatureDeepSeek V4.1-FlashClaude Opus 5.5
Official API Model ID (SDK)deepseek-reasonerclaude-opus-5-5-20260901
API ProtocolOpenAI-Compatible REST / vLLM / SGLang / HuggingFace TGIAnthropic Messages API + AWS Bedrock + Vertex AI
Release Date2026-092026-09
Knowledge CutoffJune 2026June 2026
ArchitectureCausal Encoder-Decoder (20 enc + 20 dec layers)Extended Autonomous Hybrid Reasoning Transformer
Parameters763B total (8B prefill / 16B decode active)Confidential
Enterprise Rate Limits (RPM / TPM)Unlimited (Hardware-bound on self-hosted GPU) / 10,000 RPM Cloud · Unlimited local throughput / 10M+ TPM Managed Cloud4,000 – 10,000 RPM (Tier 4 + Priority Tier) · 4,000,000 – 10,000,000 TPM
Long-Context Tier (>128K/200K)Flat rate ($0.3/1M in) across full 1000K windowStandard rate up to 200K tokens; 2x input/output tier above 200K tokens
Prompt Cache Policy & TTLAutomatic prefix caching at $0.006/1M (no extra cache-write fee)$0.4/1M cached read (90% off); 5-min default & 1-hour extended TTL
Computer Use / GUI AgentAPI / CLI Tool-Use & DOM Agent ready (no raw pixel desktop click loop)Supported (Screen coordinate grounding, browser & desktop GUI action loops)
MCP & Parallel Tool CallingNative MCP Client/Server ready · Parallel function calling · 100% Strict JSON SchemaNative MCP Client/Server ready · Parallel function calling · 100% Strict JSON Schema
Web Search Grounding & SandboxSupported via external Tavily/Exa Search & E2B/Docker Sandbox toolsNative Web Search Citations + Code Execution Tool + MCP Connectors
Official Fine-Tuning SupportFull Weights SFT, LoRA, QLoRA, DPO & GRPO RL (Unsloth / Axolotl / Llama-Factory)Custom Model Tuning via Amazon Bedrock & Prompt Distillation
Multimodal Token BillingText BPE (~4 chars/token) · Vision (~258–765 tokens per image tile)Text BPE (~4 chars/token) · Vision (~258–765 tokens per image tile)
Quantization & Min GPU VRAMBF16 / FP16, FP8 Dynamic, INT4 AWQ / GPTQ, GGUF (Q4_K_M / Q8_0) · 473 GB VRAM (4-bit Quantized) · 1640 GB VRAM (Native BF16)Cloud-Hosted Proprietary (FP8 / BF16 Tensor Core Cluster) · Zero Local VRAM Required (100% Serverless Cloud API)
Safety & Frontier ClassificationOpen-Weights System Card + Customizable Guardrail Layer (Llama Guard / ShieldGemma)Anthropic RSP ASL-2 / ASL-3 Constitutional Safety Evaluated
Enterprise Compliance (ZDR/HIPAA/SOC2)100% Air-Gapped On-Premises / Private VPC · Full HIPAA, GDPR & SOC2 ControlSOC2 Type II · GDPR · Zero Data Retention (ZDR) & HIPAA BAA Available on Enterprise Tier
Input Modalitiestext, visiontext, vision
Output Modalitiestexttext

DeepSeek V4.1-Flash vs Claude Opus 5.5: Quick Answers

Which is more intelligent, DeepSeek V4.1-Flash or Claude Opus 5.5?

Claude Opus 5.5 is more intelligent. It scores 94 compared with 58 on the composite Intelligence Index.

Which model is faster?

DeepSeek V4.1-Flash is faster, generating 110 tokens per second compared with 78 tokens per second.

Which model is cheaper to run?

DeepSeek V4.1-Flash is cheaper at $0.18 per 1M tokens blended, compared with $3.08 (7:2:1 cache:input:output ratio).

Which model has lower latency?

DeepSeek V4.1-Flash has lower latency, with a time to first token of 0.46s compared with 1.40s.

Verdict

Choose DeepSeek V4.1-Flash for extreme budget batch processing, self-hosted commodity hardware clusters, and massive long-form reasoning tasks, or choose Claude Opus 5.5 for large-scale software development agents, enterprise codebases, and mission-critical scientific synthesis.

Frequently asked questions

Which is cheaper: DeepSeek V4.1-Flash or Claude Opus 5.5?+

DeepSeek V4.1-Flash costs $0.3/1M input and $1.2/1M output tokens, while Claude Opus 5.5 costs $4/1M input and $20/1M output tokens.

Which model has a larger context window: DeepSeek V4.1-Flash or Claude Opus 5.5?+

DeepSeek V4.1-Flash supports 1M tokens whereas Claude Opus 5.5 supports 1M tokens.

AI Terminology & Guide
Explore Glossary →

Understand key metrics like context window, token pricing, reasoning mode, and SWE-bench scores in our comprehensive AI glossary.

Benchmark scores, token prices, and rate limits evolve rapidly as AI labs release model updates. Always verify current specifications and pricing on the official provider documentation.

Sources: DeepSeek & Anthropic Official Documentation