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Head-to-head comparison

Claude Opus 5 vs GLM 5.3

Claude Opus 5 (Anthropic) and GLM 5.3 (Z.ai) compared on the ModelCap Index, API price, context window, provider availability, weight access and every public benchmark board they share. Figures are the same ones shown on the live rankings; nothing here is a hidden score.

Snapshot as of 19 August 2026

As of 19 August 2026, Claude Opus 5 holds the stronger ModelCap Index position (#2 vs #7); and GLM 5.3 is 5.7× cheaper per output token ($4.40/1M vs $25.00/1M).

Which should you choose?

Choose Claude Opus 5 if…

  • you want the stronger overall ModelCap Index position — #2 against #7 (83.1 vs 78.4 points).
  • you want provider choice — 5 listed API providers against 1.
  • Artificial Analysis Intelligence Index is your yardstick — 63.1 against 59.5.

Choose GLM 5.3 if…

  • API cost matters — $4.40/1M output tokens against $25.00/1M, about 5.7× cheaper.
  • your workload is prompt-heavy — input tokens cost $1.40/1M against $5.00/1M.
  • you want the more recently listed model — GLM 5.3 was listed 18 August 2026, Claude Opus 5 24 July 2026.

Claude Opus 5 vs GLM 5.3: specs, pricing and context

Specification comparison of Claude Opus 5 and GLM 5.3
FieldClaude Opus 5AnthropicGLM 5.3Z.ai
ModelCap Index position#2#7
Index score83.178.4
EvidenceMeasuredMeasured
Input price / 1M tokens$5.00$1.40
Output price / 1M tokens$25.00$4.40
Context window1M tokens1M tokens
Max output tokens128K131K
API providers listed51
Weight accessAPI onlyAPI only
Input modalitiesText, Image, FileText
First listed24 July 202618 August 2026
PublisherAnthropicZ.ai

Evidence: 6 public benchmark observations across 6 boards · 1 public benchmark observation across 1 board. Prices are the lowest listed API offer per million tokens observed on the OpenRouter catalogue.

Benchmark scores: Claude Opus 5 vs GLM 5.3

Public benchmark boards where Claude Opus 5 or GLM 5.3 has a published result
BoardClaude Opus 5GLM 5.3Leads
Arena codingArena (LMArena)15311522–1540High—Only one result
LMArena AgentLMArena12.2%10.7%–13.6%High—Only one result
ARC-AGI-2ARC Prize Foundation90.4%Max—Only one result
ARC-AGI-3ARC Prize Foundation30.2%High—Only one result
Artificial Analysis Intelligence IndexArtificial Analysis63.1intelligence-index59.5intelligence-indexClaude Opus 5

Scores are the sources' own published figures for each model's best evaluated configuration; ModelCap never re-runs a benchmark.

Want a different pairing? Open the interactive comparison tool to swap either model for any current ranked language model.

Claude Opus 5 vs GLM 5.3: common questions

Is Claude Opus 5 better than GLM 5.3?

Claude Opus 5 ranks higher on the ModelCap Index as of 19 August 2026: #2 against #7. That is a capability ranking built from public benchmark evidence with published uncertainty; whether it is "better" for you also depends on price, context and where you can run it.

Is Claude Opus 5 cheaper than GLM 5.3?

GLM 5.3 is cheaper on output tokens: $4.40/1M against $25.00/1M. Input tokens are $5.00/1M for Claude Opus 5 and $1.40/1M for GLM 5.3. Prices are the lowest listed API offer ModelCap observed, in USD per million tokens.

Which has the bigger context window, Claude Opus 5 or GLM 5.3?

Both publish a 1M-token context window.

Which is better for coding, Claude Opus 5 or GLM 5.3?

The two models do not share a coding benchmark board on ModelCap yet, so no head-to-head coding score is published; the ModelCap Index position is the closest overall signal.

Are Claude Opus 5 and GLM 5.3 open-weight models?

Claude Opus 5: API only. GLM 5.3: API only. Open weights mean the checkpoint can be downloaded and self-hosted under its licence; API-only models are available solely through hosted endpoints.

Where can I run Claude Opus 5 and GLM 5.3?

ModelCap currently lists 5 API providers for Claude Opus 5 and 1 for GLM 5.3, from the OpenRouter catalogue snapshot the site serves; each model page lists the providers and their prices.

How current is this Claude Opus 5 vs GLM 5.3 comparison?

Every figure comes from the sealed ModelCap dataset published 19 August 2026; the page re-renders within a minute of each data refresh, and the ModelCap Index positions are the same ones shown on the live rankings.

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