ZMIME
Comparison · 3 models · Updated Nov 2, 2026

Muse Spark Open vs Claude Opus 5.5 vs GLM-5.3

Too close to call on our weighted score (Claude Opus 5.5 69, Muse Spark Open 68, GLM-5.3 63). The right pick depends on what you value most.

  1. Meta

    Muse Spark Open

    Released Oct 15, 2026New

    68/100
    • ECI155.1
    • Price$1.25 / $4.25
    • Context1.05M
  2. Anthropic

    Claude Opus 5.5

    Released Sep 22, 2026New

    69/100
    • ECI168.4
    • Price$4.00 / $20.00
    • Context1M
  3. Z.ai (Zhipu)

    GLM-5.3

    Released Aug 14, 2026

    63/100
    • ECI156.2
    • Price$1.40 / $4.40
    • Context1M
01 — Verdict

Too close to call

It is close. Our weighted score puts them within 1 points (Claude Opus 5.5 69/100, Muse Spark Open 68/100, GLM-5.3 63/100), so choose by what matters most for your work: Claude Opus 5.5 for raw capability, Muse Spark Open on price and Muse Spark Open for long inputs. 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 · GLM-5.3 156.2 · Muse Spark Open 155.1
  • Lowest priceMuse Spark OpenMuse Spark Open $2.00 · GLM-5.3 $2.15 · Claude Opus 5.5 $8.00 per 1M tokens (3:1 blend)
  • Longest contextMuse Spark OpenMuse Spark Open 1,048,576 · Claude Opus 5.5 1,000,000 · GLM-5.3 1,000,000 tokens
  • Widest inputsMuse Spark OpenMuse Spark Open: Text, Images, Audio, Video · Claude Opus 5.5: Text, Images, PDFs · GLM-5.3: Text
  • Self-hostingMuse Spark Open and GLM-5.3Publishes downloadable weights (Muse Model License)
How the score is built
MeasureWeightMuse Spark OpenClaude Opus 5.5GLM-5.3
CapabilityCapabilities Index (ECI)50%839984
Price25%34733
Inputs & features15%808045
Context window10%616060
Overall100%68/10069/10063/100
02 — Side by side

Every spec in one table

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

Muse Spark Open vs Claude Opus 5.5 vs GLM-5.3 specifications side by side
SpecificationMuse Spark OpenMetaClaude Opus 5.5AnthropicGLM-5.3Z.ai (Zhipu)
Capability
Capabilities Index (ECI)155.1168.4 (best)156.2
ECI rank#39 of 165#2 of 165 (best)#33 of 165
GPQA DiamondGraduate-level science questions88.6%90.6%90.9% (best)
FrontierMath Tiers 1–3Research-level mathematics69.8%91.2% (best)68.8%
OTIS Mock AIME 2024–2025Competition mathematics98.1%100% (best)91.1%
SimpleQA VerifiedShort factual questions56.6%72.2% (best)41.0%
Price per million tokens
Input$1.25 (best)$4.00$1.40
Output$4.25 (best)$20.00$4.40
Cached input—$0.20 (best)$0.26
Blended (3:1)$2.00 (best)$8.00$2.15
Long-context rateSame rateSame rateSame rate
Price sourceMedian of 16 providersOfficial Anthropic APIOfficial Z.AI API
Limits
Context window1,048,576 tokens (best)1,000,000 tokens1,000,000 tokens
Max output131,072 tokens (best)128,000 tokens131,072 tokens (best)
Inputs and features
TextYesYesYes
ImagesYesYesNo
PDFsNoYesNo
AudioYesNoNo
VideoYesNoNo
ReasoningYesYeslow · medium · high · xhigh · maxYeslow · high · max
Tool callingYesYesYes
Structured outputNoYesYes
Availability
WeightsOpenMuse Model LicenseProprietaryOpen
API model ID—claude-opus-5-5glm-5.3
API providers163683 (best)
ReleasedOct 15, 2026Sep 22, 2026Aug 14, 2026
Knowledge cutoffJan 4, 2026Jun 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.

  • Muse Spark Open$21.00
  • Claude Opus 5.5$80.00
  • GLM-5.3$22.80
04 — Questions

Which should you choose?

Which is better: Muse Spark Open, Claude Opus 5.5 or GLM-5.3?

It is close. Our weighted score puts them within 1 points (Claude Opus 5.5 69/100, Muse Spark Open 68/100, GLM-5.3 63/100), so choose by what matters most for your work: Claude Opus 5.5 for raw capability, Muse Spark Open on price and Muse Spark Open for long inputs. The score weighs capability 50%, price 25%, inputs & features 15%, context window 10%.

Which is cheaper, Muse Spark Open, Claude Opus 5.5 or GLM-5.3?

Muse Spark Open is cheaper at $1.25 input / $4.25 output per million tokens (median across 16 API providers). GLM-5.3 costs $1.40 input / $4.40 output per million tokens (official Z.AI 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 $2.00 per million tokens for Muse Spark Open versus $2.15 for GLM-5.3 (1.1× as much) and $8.00 for Claude Opus 5.5 (4× 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), GLM-5.3 156.2 (#33 of 165) and Muse Spark Open 155.1 (#39 of 165). Their confidence ranges do not overlap (165.4–173.0 vs 154.3–158.5), so the gap is a real one. On individual benchmarks: GPQA Diamond — GLM-5.3 90.9%, Claude Opus 5.5 90.6%, Muse Spark Open 88.6%; FrontierMath Tiers 1–3 — Claude Opus 5.5 91.2%, Muse Spark Open 69.8%, GLM-5.3 68.8%; OTIS Mock AIME 2024–2025 — Claude Opus 5.5 100%, Muse Spark Open 98.1%, GLM-5.3 91.1%; SimpleQA Verified — Claude Opus 5.5 72.2%, Muse Spark Open 56.6%, GLM-5.3 41.0%.

Which is better for coding?

There are no published SWE-bench Verified results for Muse Spark Open, Claude Opus 5.5 and GLM-5.3 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?

Muse Spark Open has the largest context window at 1,048,576 tokens, against 1,000,000 for Claude Opus 5.5 and 1,000,000 for GLM-5.3. Maximum output per response: Muse Spark Open up to 131,072, Claude Opus 5.5 up to 128,000, GLM-5.3 up to 131,072 tokens.

Which can read images, PDFs, audio or video?

Muse Spark Open accepts text, images, audio and video; Claude Opus 5.5 accepts text, images and PDFs; GLM-5.3 accepts text. Muse Spark Open handles the widest range of inputs.

Are any of these open source?

Muse Spark Open and GLM-5.3 publishes its weights (Muse Model License) and can be self-hosted; Claude Opus 5.5 is proprietary.

Which is newer?

Muse Spark Open is the newest, released Oct 15, 2026. Claude Opus 5.5 came out Sep 22, 2026; GLM-5.3 came out Aug 14, 2026. Knowledge cutoff: Muse Spark Open Jan 4, 2026, Claude Opus 5.5 Jun 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.