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Claude Sonnet 4 vs GLM-4.5

A complete head-to-head: pricing, context window, benchmarks, modality coverage, and openness, with a programmatic verdict synthesized from the underlying data.

Updated

Claude Sonnet 4 specs · GLM-4.5 specs
Verdict by category
  • PriceClaude Sonnet 4

    Claude Sonnet 4 publishes pricing ($15.00 / 1M output tokens) while GLM-4.5 does not.

  • Context windowClaude Sonnet 4

    Claude Sonnet 4 accepts 200K tokens vs 128K, 1.6× the room for long documents and codebases.

  • BenchmarksTie

    No directly comparable public benchmarks are available for both models, check the spec sheets for individual scores.

  • ModalitiesTie

    Both handle text, vision.

  • OpennessGLM-4.5

    GLM-4.5 ships open weights (MIT); Claude Sonnet 4 is API-only.

On balance Claude Sonnet 4 edges ahead, winning 2 of 5 categories against GLM-4.5's 1. Claude Sonnet 4 publishes pricing ($15.00 / 1M output tokens) while GLM-4.5 does not. Claude Sonnet 4 accepts 200K tokens vs 128K, 1.6× the room for long documents and codebases.

No directly comparable public benchmarks are available for both models, check the spec sheets for individual scores. Both target the same set of modalities (text, vision), so the deciding factors are price, context, and raw quality. GLM-4.5 ships open weights (MIT); Claude Sonnet 4 is API-only.

GLM-4.5 is the newer of the two, released 2 months after Claude Sonnet 4, which usually means a more recent knowledge cutoff and updated safety post-training. Claude Sonnet 4 is usually picked for coding llm and rag workloads, while GLM-4.5 sees more deployments in chinese llm and open source llm. If pricing matters more than every last benchmark point, run the numbers in the calculator below before committing.

Side-by-side specs

SpecClaude Sonnet 4GLM-4.5
ProviderAnthropicOther
ReleasedMay 2025Jul 2025
Modalitiestext, visiontext, vision
Context window200K tokens128K tokens
Max output,,
Input · 1M$3.00 / 1M tokensPricing not published
Output · 1M$15.00 / 1M tokensPricing not published
Knowledge cutoff2025-03,
Open weightsNoYes (MIT)
API availableYesYes

Pricing at scale

What you'd actually pay at typical workloads. Numbers come from each model's published per-million-token rates.

  • Light usage, 100k in / 50k out per day$31.50 vs ,
  • Heavy usage, 1M in / 500k out per day$315 vs ,
  • RAG workload, 5M in / 200k out per day$540 vs ,

Light usage, 100k in / 50k out per day: pricing not directly comparable (one or both models are missing public per-token rates). Heavy usage, 1M in / 500k out per day: pricing not directly comparable (one or both models are missing public per-token rates). RAG workload, 5M in / 200k out per day: pricing not directly comparable (one or both models are missing public per-token rates).

Price calculator

Estimated spend for the listed models at your usage. Numbers are derived from each model's published per-million-token rates.

  • Claude Sonnet 4$1.05
  • GLM-4.5Pricing unavailable

Benchmarks compared

Only sourced numbers. Where a benchmark is missing for one model we show the available value rather than fabricating the other.

Claude Sonnet 4GLM-4.5
  • SWE-bench Verified65.0
Pick Claude Sonnet 4 if

Claude Sonnet 4 fits when…

  • Solid all-rounder
  • Mature deployment ecosystem
  • Long-context tasks, handles 200K tokens vs 128K for GLM-4.5.
Pick GLM-4.5 if

GLM-4.5 fits when…

  • MIT license
  • Strong Chinese
  • Multimodal
  • Self-hosting and on-prem requirements, open weights (MIT).
Don't want either?

Consider Claude Opus 4.7

Anthropic's mid-2026 flagship, ahead on SWE-bench, agent reliability, and writing quality.

See Claude Opus 4.7 specsClaude Sonnet 4 vs Claude Opus 4.7GLM-4.5 vs Claude Opus 4.7

Frequently asked

  • Is Claude Sonnet 4 or GLM-4.5 cheaper?
    Per-token pricing isn't published for at least one of these models, check each model's spec page for current rates.
  • Which has the larger context window?
    Claude Sonnet 4 accepts 200K tokens vs 128K for GLM-4.5.
  • Is Claude Sonnet 4 or GLM-4.5 better for coding?
    Both Claude Sonnet 4 and GLM-4.5 are competitive on coding benchmarks. See each model's individual spec page for HumanEval and SWE-bench scores where published. For an opinionated pick, consult our Best LLM for Coding ranking.
  • Are either of these models open source?
    GLM-4.5 ships open weights (MIT). Claude Sonnet 4 is API-only.
  • When were Claude Sonnet 4 and GLM-4.5 released?
    Claude Sonnet 4 was released by Anthropic on 2025-05-22. GLM-4.5 was released by Other on 2025-07-28.
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