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Head-to-head comparison

GPT-6 Astra vs GLM 5.3

GPT-6 Astra (OpenAI) 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 9 September 2026

As of 9 September 2026, GPT-6 Astra holds the stronger ModelCap Index position (#1 vs #8); and GLM 5.3 is 11.4× cheaper per output token ($4.40/1M vs $50.00/1M).

Which should you choose?

Choose GPT-6 Astra if…

  • you want the stronger overall ModelCap Index position — #1 against #8 (93.7 vs 82.1 points).
  • LMArena Agent is your yardstick — 12.5% against 2.6%.
  • AA Intelligence Index is your yardstick — 52.8 against 44.9.
  • AA Terminal-Bench 2.1 is your yardstick — 88.4% against 83.9%.
  • AA Humanity's Last Exam is your yardstick — 54.7% against 42.3%.
  • Terminal-Bench 4.0 is your yardstick — 58.2% against 41.8%.
  • you want the more recently listed model — GPT-6 Astra was listed 4 September 2026, GLM 5.3 18 August 2026.

Choose GLM 5.3 if…

  • API cost matters — $4.40/1M output tokens against $50.00/1M, about 11.4× cheaper.
  • your workload is prompt-heavy — input tokens cost $1.40/1M against $10.00/1M.
  • you want provider choice — 26 listed API providers against 2.

GPT-6 Astra vs GLM 5.3: specs, pricing and context

Specification comparison of GPT-6 Astra and GLM 5.3
FieldGPT-6 AstraOpenAIGLM 5.3Z.ai
ModelCap Index position#1#8
Index score93.782.1
EvidenceMeasuredMeasured
Input price / 1M tokens$10.00$1.40
Output price / 1M tokens$50.00$4.40
Context window1M tokens1M tokens
Max output tokens128K944K
API providers listed226
Weight accessAPI onlyRestricted license
Input modalitiesFile, Image, TextText
First listed4 September 202618 August 2026
PublisherOpenAIZ.ai

Evidence: 4 public benchmark observations across 4 boards · 4 public benchmark observations across 4 boards. Prices are the lowest listed API offer per million tokens observed on the OpenRouter catalogue.

Benchmark scores: GPT-6 Astra vs GLM 5.3

Public benchmark boards where GPT-6 Astra or GLM 5.3 has a published result
BoardGPT-6 AstraGLM 5.3Leads
Arena codingArena (LMArena)—15281514–1541MaxOnly one result
LMArena AgentLMArena12.5%10.4%–14.7%Max2.6%1.9%–3.2%MaxGPT-6 Astra
ARC-AGI-2ARC Prize Foundation95.0%Max—Only one result
ARC-AGI-3ARC Prize Foundation62.7%Max—Only one result
AA Intelligence IndexArtificial Analysis52.8intelligence-index:v4.3:max44.9intelligence-index:v4.3:maxGPT-6 Astra
AA Terminal-Bench 2.1Artificial Analysis88.4%terminal-bench:2.1:terminus-2:e2b:pass-at-1:3-repeats:source-model="GPT-6 Astra (max)":reasoning=true83.9%terminal-bench:2.1:terminus-2:e2b:pass-at-1:3-repeats:source-model="GLM-5.3 (max)":reasoning=trueGPT-6 Astra
AA Humanity's Last ExamArtificial Analysis54.7%hle:may-2025:text-only-2158:no-tools:pass-at-1:source-model="GPT-6 Astra (max)":reasoning=true42.3%hle:may-2025:text-only-2158:no-tools:pass-at-1:source-model="GLM-5.3 (max)":reasoning=trueGPT-6 Astra
Terminal-Bench 4.0Terminal-Bench (Laude Institute)58.2%55.4%–61.0%Codex · Max41.8%38.6%–45.1%Claude Code · MaxGPT-6 Astra

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 Astra vs GLM 5.3: common questions

Is GPT-6 Astra better than GLM 5.3?

GPT-6 Astra ranks higher on the ModelCap Index as of 9 September 2026: #1 against #8. 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 Astra cheaper than GLM 5.3?

GLM 5.3 is cheaper on output tokens: $4.40/1M against $50.00/1M. Input tokens are $10.00/1M for GPT-6 Astra and $1.40/1M for GLM 5.3. 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 $45.00 for GPT-6 Astra versus $5.00 for GLM 5.3. GLM 5.3 costs 88.9% 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 Astra or GLM 5.3?

Both publish a 1M-token context window.

Which is better for coding, GPT-6 Astra or GLM 5.3?

AA Terminal-Bench 2.1: GPT-6 Astra 88.4%, GLM 5.3 83.9% — GPT-6 Astra leads. Terminal-Bench 4.0: GPT-6 Astra 58.2%, GLM 5.3 41.8% — GPT-6 Astra leads.

Are GPT-6 Astra and GLM 5.3 open-weight models?

GPT-6 Astra: API only. GLM 5.3: Restricted license. 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 Astra and GLM 5.3?

ModelCap currently lists 2 API providers for GPT-6 Astra and 26 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 GPT-6 Astra vs GLM 5.3 comparison?

Every figure comes from the sealed ModelCap dataset published 9 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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