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Head-to-head comparison

GPT-5.3-Codex vs GLM 5.2

GPT-5.3-Codex (OpenAI) and GLM 5.2 (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 17 August 2026

As of 17 August 2026, GLM 5.2 holds the stronger ModelCap Index position (#11 vs #20); GLM 5.2 is 9.6× cheaper per output token ($1.45/1M vs $14.00/1M); GLM 5.2 offers the longer context window (1M vs 400K tokens); and GLM 5.2 ships open weights.

Which should you choose?

Choose GPT-5.3-Codex if…

  • ModelCap publishes no field on which GPT-5.3-Codex leads GLM 5.2 for this pair.

Choose GLM 5.2 if…

  • you want the stronger overall ModelCap Index position — #11 against #20 (73.8 vs 66.4 points).
  • API cost matters — $1.45/1M output tokens against $14.00/1M, about 9.6× cheaper.
  • your workload is prompt-heavy — input tokens cost $0.462/1M against $1.75/1M.
  • you need the longer context window — 1M tokens against 400K.
  • you want to self-host: GLM 5.2 ships open weights while GPT-5.3-Codex is api only.
  • you want provider choice — 27 listed API providers against 2.
  • Artificial Analysis Intelligence Index is your yardstick — 52.6 against 45.5.
  • you want the more recently listed model — GLM 5.2 was listed 16 June 2026, GPT-5.3-Codex 24 February 2026.

GPT-5.3-Codex vs GLM 5.2: specs, pricing and context

Specification comparison of GPT-5.3-Codex and GLM 5.2
FieldGPT-5.3-CodexOpenAIGLM 5.2Z.ai
ModelCap Index position#20#11
Index score66.473.8
EvidenceMeasuredMeasured
Input price / 1M tokens$1.75$0.462
Output price / 1M tokens$14.00$1.45
Context window400K tokens1M tokens
Max output tokens128K131K
API providers listed227
Weight accessAPI onlyOpen weights
Input modalitiesText, Image, FileText
First listed24 February 202616 June 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-5.3-Codex vs GLM 5.2

Public benchmark boards where GPT-5.3-Codex or GLM 5.2 has a published result
BoardGPT-5.3-CodexGLM 5.2Leads
Arena codingArena (LMArena)—15061498–1514MaxOnly one result
LMArena AgentLMArena—6.7%5.8%–7.6%MaxOnly one result
ARC-AGI-2ARC Prize Foundation—22.8%Only one result
Artificial Analysis Intelligence IndexArtificial Analysis45.5intelligence-index52.6intelligence-indexGLM 5.2

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-5.3-Codex vs GLM 5.2: common questions

Is GPT-5.3-Codex better than GLM 5.2?

GLM 5.2 ranks higher on the ModelCap Index as of 17 August 2026: #11 against #20. 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 GPT-5.3-Codex cheaper than GLM 5.2?

GLM 5.2 is cheaper on output tokens: $1.45/1M against $14.00/1M. Input tokens are $1.75/1M for GPT-5.3-Codex and $0.462/1M for GLM 5.2. Prices are the lowest listed API offer ModelCap observed, in USD per million tokens.

Which has the bigger context window, GPT-5.3-Codex or GLM 5.2?

GLM 5.2 has the larger context window: 1M tokens against 400K.

Which is better for coding, GPT-5.3-Codex or GLM 5.2?

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-5.3-Codex and GLM 5.2 open-weight models?

GPT-5.3-Codex: API only. GLM 5.2: 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-5.3-Codex and GLM 5.2?

ModelCap currently lists 2 API providers for GPT-5.3-Codex and 27 for GLM 5.2, from the OpenRouter catalogue snapshot the site serves; each model page lists the providers and their prices.

How current is this GPT-5.3-Codex vs GLM 5.2 comparison?

Every figure comes from the sealed ModelCap dataset published 17 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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