ZMIME
Comparison · 3 models · Updated Nov 2, 2026

Claude Opus 5.5 vs DeepSeek V4.1 Flash 1017 vs GPT-6.1 Sol

DeepSeek V4.1 Flash 1017 comes out ahead, 79 to 72 and 69 on our weighted score, and it is the cheaper option too.

  1. Anthropic

    Claude Opus 5.5

    Released Sep 22, 2026New

    69/100
    • ECI168.4
    • Price$4.00 / $20.00
    • Context1M
    Full specs Remove Claude Opus 5.5
  2. Our pick

    DeepSeek

    DeepSeek V4.1 Flash 1017

    Released Oct 17, 2026New

    79/100
    • ECI158.8
    • Price$0.15 / $0.60
    • Context1M
    Full specs Remove DeepSeek V4.1 Flash 1017

  3. OpenAI

    GPT-6.1 Sol

    Released Sep 29, 2026New

    72/100
    • ECI167.8
    • Price$2.00 / $10.00
    • Context1.05M
    Full specs Remove GPT-6.1 Sol
01 — Verdict

DeepSeek V4.1 Flash 1017 is our pick

DeepSeek V4.1 Flash 1017 is the better all-round choice, scoring 79/100 against GPT-6.1 Sol (72) and Claude Opus 5.5 (69). It leads on price. The score weighs capability 50%, price 25%, inputs & features 15%, context window 10%.

  • CapabilityClaude Opus 5.5Capabilities Index (ECI): Claude Opus 5.5 168.4 · GPT-6.1 Sol 167.8 · DeepSeek V4.1 Flash 1017 158.8
  • Lowest priceDeepSeek V4.1 Flash 1017DeepSeek V4.1 Flash 1017 $0.263 · GPT-6.1 Sol $4.00 · Claude Opus 5.5 $8.00 per 1M tokens (3:1 blend)
  • Longest contextGPT-6.1 SolGPT-6.1 Sol 1,050,000 · Claude Opus 5.5 1,000,000 · DeepSeek V4.1 Flash 1017 1,000,000 tokens
  • Widest inputsClaude Opus 5.5 and GPT-6.1 SolClaude Opus 5.5: Text, Images, PDFs · DeepSeek V4.1 Flash 1017: Text, Images · GPT-6.1 Sol: Text, Images, PDFs
  • Self-hostingDeepSeek V4.1 Flash 1017Publishes downloadable weights (MIT)
How the score is built
MeasureWeightClaude Opus 5.5DeepSeek V4.1 Flash 1017GPT-6.1 Sol
CapabilityCapabilities Index (ECI)50%998799
Price25%77420
Inputs & features15%807080
Context window10%606061
Overall100%69/10079/10072/100
02 — Side by side

Every spec in one table

Highlighted cells lead their row. Dashes mean the data is not published.

Claude Opus 5.5 vs DeepSeek V4.1 Flash 1017 vs GPT-6.1 Sol specifications side by side
SpecificationClaude Opus 5.5AnthropicDeepSeek V4.1 Flash 1017DeepSeekGPT-6.1 SolOpenAI
Capability
Capabilities Index (ECI)168.4 (best)158.8167.8
ECI rank#2 of 165 (best)#19 of 165#4 of 165
GPQA DiamondGraduate-level science questions90.6%93.2%95.4% (best)
FrontierMath Tiers 1–3Research-level mathematics91.2%71.2%93.7% (best)
OTIS Mock AIME 2024–2025Competition mathematics100% (best)99.4%100% (best)
SimpleQA VerifiedShort factual questions72.2%42.5%73.9% (best)
Price per million tokens
Input$4.00$0.15 (best)$2.00
Output$20.00$0.60 (best)$10.00
Cached input$0.20$0.003 (best)$0.10
Blended (3:1)$8.00$0.263 (best)$4.00
Long-context rateSame rateSame rateOver 272K: $4.00 / $15.00
Price sourceOfficial Anthropic APIOfficial DeepSeek APIOfficial OpenAI API
Limits
Context window1,000,000 tokens1,000,000 tokens1,050,000 tokens (best)
Max output128,000 tokens384,000 tokens (best)128,000 tokens
Inputs and features
TextYesYesYes
ImagesYesYesYes
PDFsYesNoYes
AudioNoNoNo
VideoNoNoNo
ReasoningYeslow · medium · high · xhigh · maxYeslow · high · maxYeslow · medium · high · xhigh · max
Tool callingYesYesYes
Structured outputYesYesYes
Availability
WeightsProprietaryOpenMITProprietary
API model IDclaude-opus-5-5deepseek-flashgpt-6.1-sol
API providers3640 (best)33
ReleasedSep 22, 2026Oct 17, 2026Sep 29, 2026
Knowledge cutoffJun 2026May 2025Apr 30, 2026
03 — Cost

What would a month cost?

Enter your expected volume in millions of tokens. List prices only; caching and batch discounts would lower these.

  • Claude Opus 5.5$80.00
  • DeepSeek V4.1 Flash 1017$2.70
  • GPT-6.1 Sol$40.00
04 — Questions

Which should you choose?

Which is better: Claude Opus 5.5, DeepSeek V4.1 Flash 1017 or GPT-6.1 Sol?

DeepSeek V4.1 Flash 1017 is the better all-round choice, scoring 79/100 against GPT-6.1 Sol (72) and Claude Opus 5.5 (69). It leads on price. The score weighs capability 50%, price 25%, inputs & features 15%, context window 10%.

Which is cheaper, Claude Opus 5.5, DeepSeek V4.1 Flash 1017 or GPT-6.1 Sol?

DeepSeek V4.1 Flash 1017 is cheaper at $0.15 input / $0.60 output per million tokens (official DeepSeek API price). GPT-6.1 Sol costs $2.00 input / $10.00 output per million tokens (official OpenAI API price); Claude Opus 5.5 costs $4.00 input / $20.00 output per million tokens (official Anthropic API price). At a typical mix of three input tokens to one output token, that is $0.263 per million tokens for DeepSeek V4.1 Flash 1017 versus $4.00 for GPT-6.1 Sol (15× as much) and $8.00 for Claude Opus 5.5 (30× as much).

Which scores higher on benchmarks?

Claude Opus 5.5 scores higher on the Capabilities Index (ECI): Claude Opus 5.5 168.4 (#2 of 165), GPT-6.1 Sol 167.8 (#4 of 165) and DeepSeek V4.1 Flash 1017 158.8 (#19 of 165). The confidence ranges of the top two overlap (165.4–173.0 vs 164.3–172.5), so treat the gap as small. On individual benchmarks: GPQA Diamond — GPT-6.1 Sol 95.4%, DeepSeek V4.1 Flash 1017 93.2%, Claude Opus 5.5 90.6%; FrontierMath Tiers 1–3 — GPT-6.1 Sol 93.7%, Claude Opus 5.5 91.2%, DeepSeek V4.1 Flash 1017 71.2%; OTIS Mock AIME 2024–2025 — Claude Opus 5.5 100%, GPT-6.1 Sol 100%, DeepSeek V4.1 Flash 1017 99.4%; SimpleQA Verified — GPT-6.1 Sol 73.9%, Claude Opus 5.5 72.2%, DeepSeek V4.1 Flash 1017 42.5%.

Which is better for coding?

There are no published SWE-bench Verified results for Claude Opus 5.5, DeepSeek V4.1 Flash 1017 and GPT-6.1 Sol yet, so there is no like-for-like coding score. On overall capability, Claude Opus 5.5 leads, which tends to carry over to coding, but test on your own codebase. All three support tool calling for agent workflows.

Which has the bigger context window?

GPT-6.1 Sol has the largest context window at 1,050,000 tokens, against 1,000,000 for Claude Opus 5.5 and 1,000,000 for DeepSeek V4.1 Flash 1017. Maximum output per response: Claude Opus 5.5 up to 128,000, DeepSeek V4.1 Flash 1017 up to 384,000, GPT-6.1 Sol up to 128,000 tokens.

Which can read images, PDFs, audio or video?

Claude Opus 5.5 accepts text, images and PDFs; DeepSeek V4.1 Flash 1017 accepts text and images; GPT-6.1 Sol accepts text, images and PDFs. Claude Opus 5.5 handles the widest range of inputs.

Are any of these open source?

DeepSeek V4.1 Flash 1017 publishes its weights (MIT) and can be self-hosted; Claude Opus 5.5 and GPT-6.1 Sol is proprietary.

Which is newer?

DeepSeek V4.1 Flash 1017 is the newest, released Oct 17, 2026. GPT-6.1 Sol came out Sep 29, 2026; Claude Opus 5.5 came out Sep 22, 2026. Knowledge cutoff: Claude Opus 5.5 Jun 2026, DeepSeek V4.1 Flash 1017 May 2025, GPT-6.1 Sol Apr 30, 2026.

How do you decide the winner?

Each model gets a 0–100 score on capability (50%, independent benchmark results); price (25%, blended price per million tokens (3 input : 1 output), log scale); inputs & features (15%, image, PDF, audio and video input, tool calling, structured output and reasoning); context window (10%, maximum tokens per request, log scale). Dimensions missing for any model are dropped and the remaining weights rescaled, so every model is judged on the same evidence. Specs and prices come from public model listings and the labs’ own API pages; capability scores come from independent benchmark runs. Data updated Nov 2, 2026.

05 — Keep comparing

Related comparisons