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Head-to-head comparison

GPT-6.1 Sol vs GLM 5.3 Flash

GPT-6.1 Sol (OpenAI) and GLM 5.3 Flash (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 30 September 2026

As of 30 September 2026, GPT-6.1 Sol holds the stronger ModelCap Index position (#3 vs #17); GLM 5.3 Flash is 20× cheaper per output token ($0.50/1M vs $10.00/1M); and GLM 5.3 Flash ships open weights.

Which should you choose?

Choose GPT-6.1 Sol if…

  • you want the stronger overall ModelCap Index position — #3 against #17 (88.3 vs 78.9 points).
  • AA Intelligence Index is your yardstick — 51.8 against 41.8.
  • AA Humanity's Last Exam is your yardstick — 52.9% against 39.9%.
  • you want the more recently listed model — GPT-6.1 Sol was listed 29 September 2026, GLM 5.3 Flash 26 August 2026.

Choose GLM 5.3 Flash if…

  • API cost matters — $0.50/1M output tokens against $10.00/1M, about 20× cheaper.
  • your workload is prompt-heavy — input tokens cost $0.15/1M against $2.00/1M.
  • you want to self-host: GLM 5.3 Flash ships open weights while GPT-6.1 Sol is api only.
  • you want provider choice — 31 listed API providers against 2.

GPT-6.1 Sol vs GLM 5.3 Flash: specs, pricing and context

Specification comparison of GPT-6.1 Sol and GLM 5.3 Flash
FieldGPT-6.1 SolOpenAIGLM 5.3 FlashZ.ai
ModelCap Index position#3#17
Index score88.378.9
EvidenceMeasuredMeasured
Input price / 1M tokens$2.00$0.15
Output price / 1M tokens$10.00$0.50
Context window1M tokens1M tokens
Max output tokens128K944K
API providers listed231
Weight accessAPI onlyOpen weights
Input modalitiesFile, Image, TextText, Image, Video
First listed29 September 202626 August 2026
PublisherOpenAIZ.ai

Evidence: 1 public benchmark observation across 1 board · 5 public benchmark observations across 5 boards. Prices are the lowest listed API offer per million tokens observed on the OpenRouter catalogue.

Benchmark scores: GPT-6.1 Sol vs GLM 5.3 Flash

Public benchmark boards where GPT-6.1 Sol or GLM 5.3 Flash has a published result
BoardGPT-6.1 SolGLM 5.3 FlashLeads
Arena codingArena (LMArena)—15231514–1531Only one result
LMArena AgentLMArena—-0.1%-0.6%–0.4%Only one result
ARC-AGI-2ARC Prize Foundation—65.8%MaxOnly one result
AA Intelligence IndexArtificial Analysis51.8Max41.8ReasoningGPT-6.1 Sol
AA Humanity's Last ExamArtificial Analysis52.9%Max39.9%ReasoningGPT-6.1 Sol

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.

GPT-6.1 Sol vs GLM 5.3 Flash: common questions

Is GPT-6.1 Sol better than GLM 5.3 Flash?

GPT-6.1 Sol ranks higher on the ModelCap Index as of 30 September 2026: #3 against #17. 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. Their published uncertainty intervals overlap, so the rank difference alone does not establish a reliable capability advantage for your workload.

Is GPT-6.1 Sol cheaper than GLM 5.3 Flash?

GLM 5.3 Flash is cheaper on output tokens: $0.50/1M against $10.00/1M. Input tokens are $2.00/1M for GPT-6.1 Sol and $0.15/1M for GLM 5.3 Flash. Prices are the lowest listed API offer ModelCap observed, in USD per million tokens. For 1,000 requests with 2,000 input and 500 output tokens each (2M input + 0.5M output), the listed-rate estimate is $9.00 for GPT-6.1 Sol versus $0.55 for GLM 5.3 Flash. GLM 5.3 Flash costs 93.9% less in this scenario. This excludes caching, batch discounts, prompt-length tiers, tool charges and retries; verify the selected endpoint before budgeting.

Which has the bigger context window, GPT-6.1 Sol or GLM 5.3 Flash?

Both publish a 1M-token context window.

Which is better for coding, GPT-6.1 Sol or GLM 5.3 Flash?

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 GPT-6.1 Sol and GLM 5.3 Flash open-weight models?

GPT-6.1 Sol: API only. GLM 5.3 Flash: Open weights. 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 GPT-6.1 Sol and GLM 5.3 Flash?

ModelCap currently lists 2 API providers for GPT-6.1 Sol and 31 for GLM 5.3 Flash, from the OpenRouter catalogue snapshot the site serves; each model page lists the providers and their prices.

How current is this GPT-6.1 Sol vs GLM 5.3 Flash comparison?

Every figure comes from the sealed ModelCap dataset published 30 September 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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