ZMIME
Comparison · 2 models · Updated Oct 4, 2026

Claude Mythos 5 vs GPT-5.6 Cyber

Claude Mythos 5 comes out ahead, 36 to 30 on our weighted score, and it is the cheaper option too.

  1. Our pick

    Anthropic

    Claude Mythos 5

    Released Jun 9, 2026

    36/100
    • ECI—
    • Price$10.00 / $50.00
    • Context1M
  2. OpenAI

    GPT-5.6 Cyber

    Released Aug 7, 2026

    30/100
    • ECI—
    • Price$12.50 / $75.00
    • Context400K
  3. Add a model

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01 — Verdict

Claude Mythos 5 is our pick

Claude Mythos 5 is the better all-round choice, scoring 36/100 against GPT-5.6 Cyber (30). It leads on inputs & features and context window. The score weighs price 50%, inputs & features 30%, context window 20%. None of the shared benchmarks cover every model here yet, so capability is left out of this verdict.

  • CapabilityNot enough dataNo independent benchmark covers every model here yet
  • Lowest priceClaude Mythos 5Claude Mythos 5 $20.00 · GPT-5.6 Cyber $28.13 per 1M tokens (3:1 blend)
  • Longest contextClaude Mythos 5Claude Mythos 5 1,000,000 · GPT-5.6 Cyber 400,000 tokens
  • Widest inputsClaude Mythos 5Claude Mythos 5: Text, Images, PDFs · GPT-5.6 Cyber: Text, Images
  • Self-hostingNo open weightsBoth are available only through APIs
How the score is built
MeasureWeightClaude Mythos 5GPT-5.6 Cyber
Price50%00
Inputs & features30%8070
Context window20%6044
Overall100%36/10030/100

Left out because at least one model lacks the data: capability. The remaining weights were rescaled.

02 — Side by side

Every spec in one table

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

Claude Mythos 5 vs GPT-5.6 Cyber specifications side by side
SpecificationClaude Mythos 5AnthropicGPT-5.6 CyberOpenAI
Capability
Capabilities Index (ECI)——
ECI rank——
Price per million tokens
Input$10.00 (best)$12.50
Output$50.00 (best)$75.00
Cached input—$1.25
Blended (3:1)$20.00 (best)$28.13
Long-context rateSame rateSame rate
Price sourceMedian of 2 providersOfficial OpenAI API
Limits
Context window1,000,000 tokens (best)400,000 tokens
Max output128,000 tokens128,000 tokens
Inputs and features
TextYesYes
ImagesYesYes
PDFsYesNo
AudioNoNo
VideoNoNo
ReasoningYesYeslow · medium · high · xhigh · max
Tool callingYesYes
Structured outputYesYes
Availability
WeightsProprietaryProprietary
API model ID—gpt-daybreak-red-latest
API providers2 (best)1
ReleasedJun 9, 2026Aug 7, 2026
Knowledge cutoffJan 31, 2026Feb 16, 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 Mythos 5$200.00
  • GPT-5.6 Cyber$275.00
04 — Questions

Which should you choose?

Which is better: Claude Mythos 5 or GPT-5.6 Cyber?

Claude Mythos 5 is the better all-round choice, scoring 36/100 against GPT-5.6 Cyber (30). It leads on inputs & features and context window. The score weighs price 50%, inputs & features 30%, context window 20%. None of the shared benchmarks cover every model here yet, so capability is left out of this verdict.

Which is cheaper, Claude Mythos 5 or GPT-5.6 Cyber?

Claude Mythos 5 is cheaper at $10.00 input / $50.00 output per million tokens (median across 2 API providers). GPT-5.6 Cyber costs $12.50 input / $75.00 output per million tokens (official OpenAI API price). At a typical mix of three input tokens to one output token, that is $20.00 per million tokens for Claude Mythos 5 versus $28.13 for GPT-5.6 Cyber (1.4× as much).

Which scores higher on benchmarks?

There is no independent benchmark that covers both models yet. Claude Mythos 5 has not been scored yet and GPT-5.6 Cyber has not been scored yet.

Which is better for coding?

There are no published SWE-bench Verified results for Claude Mythos 5 and GPT-5.6 Cyber yet, so there is no like-for-like coding score. Test both on a sample of your own tasks. Both support tool calling for agent workflows.

Which has the bigger context window?

Claude Mythos 5 has the largest context window at 1,000,000 tokens, against 400,000 for GPT-5.6 Cyber. Maximum output per response: Claude Mythos 5 up to 128,000, GPT-5.6 Cyber up to 128,000 tokens.

Which can read images, PDFs, audio or video?

Claude Mythos 5 accepts text, images and PDFs; GPT-5.6 Cyber accepts text and images. Claude Mythos 5 handles the widest range of inputs.

Are any of these open source?

No. Claude Mythos 5 and GPT-5.6 Cyber are proprietary and only available through APIs and apps.

Which is newer?

GPT-5.6 Cyber is the newest, released Aug 7, 2026. Claude Mythos 5 came out Jun 9, 2026. Knowledge cutoff: Claude Mythos 5 Jan 31, 2026, GPT-5.6 Cyber Feb 16, 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 Oct 4, 2026.