Skip to content
ModelCap

Head-to-head comparison

GPT-5.5 vs GLM 5 Turbo

GPT-5.5 (OpenAI) and GLM 5 Turbo (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 18 August 2026

As of 18 August 2026, GPT-5.5 holds the stronger ModelCap Index position (#8 vs #39); GLM 5 Turbo is 7.5× cheaper per output token ($4.00/1M vs $30.00/1M); and GPT-5.5 offers the longer context window (1M vs 203K tokens).

Which should you choose?

Choose GPT-5.5 if…

  • you want the stronger overall ModelCap Index position — #8 against #39 (75.7 vs 53.9 points).
  • you need the longer context window — 1M tokens against 203K.
  • you want provider choice — 3 listed API providers against 1.
  • WildClawBench OpenClaw is your yardstick — 58.2 against 33.9.
  • Artificial Analysis Intelligence Index is your yardstick — 56.3 against 39.1.
  • you want the more recently listed model — GPT-5.5 was listed 24 April 2026, GLM 5 Turbo 15 March 2026.

Choose GLM 5 Turbo if…

  • API cost matters — $4.00/1M output tokens against $30.00/1M, about 7.5× cheaper.
  • your workload is prompt-heavy — input tokens cost $1.20/1M against $5.00/1M.

GPT-5.5 vs GLM 5 Turbo: specs, pricing and context

Specification comparison of GPT-5.5 and GLM 5 Turbo
FieldGPT-5.5OpenAIGLM 5 TurboZ.ai
ModelCap Index position#8#39
Index score75.753.9
EvidenceMeasuredMeasured
Input price / 1M tokens$5.00$1.20
Output price / 1M tokens$30.00$4.00
Context window1M tokens203K tokens
Max output tokens128K131K
API providers listed31
Weight accessAPI onlyAPI only
Input modalitiesFile, Image, TextText
First listed24 April 202615 March 2026
PublisherOpenAIZ.ai

Evidence: 8 public benchmark observations across 8 boards · 2 public benchmark observations across 2 boards. Prices are the lowest listed API offer per million tokens observed on the OpenRouter catalogue.

Benchmark scores: GPT-5.5 vs GLM 5 Turbo

Public benchmark boards where GPT-5.5 or GLM 5 Turbo has a published result
BoardGPT-5.5GLM 5 TurboLeads
Arena codingArena (LMArena)15201513–1526High—Only one result
LMArena AgentLMArena8.9%7.9%–9.9%X-High—Only one result
ARC-AGI-2ARC Prize Foundation85.0%X-High—Only one result
ARC-AGI-3ARC Prize Foundation0.4%High—Only one result
Terminal-Bench 2.1 Terminus 2Terminal-Bench78.0X-High—Only one result
WildClawBench OpenClawWildClawBench58.233.9GPT-5.5
Artificial Analysis Intelligence IndexArtificial Analysis56.3intelligence-index39.1intelligence-indexGPT-5.5

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.

GPT-5.5 vs GLM 5 Turbo: common questions

Is GPT-5.5 better than GLM 5 Turbo?

GPT-5.5 ranks higher on the ModelCap Index as of 18 August 2026: #8 against #39. 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-5.5 cheaper than GLM 5 Turbo?

GLM 5 Turbo is cheaper on output tokens: $4.00/1M against $30.00/1M. Input tokens are $5.00/1M for GPT-5.5 and $1.20/1M for GLM 5 Turbo. Prices are the lowest listed API offer ModelCap observed, in USD per million tokens.

Which has the bigger context window, GPT-5.5 or GLM 5 Turbo?

GPT-5.5 has the larger context window: 1M tokens against 203K.

Which is better for coding, GPT-5.5 or GLM 5 Turbo?

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-5.5 and GLM 5 Turbo open-weight models?

GPT-5.5: API only. GLM 5 Turbo: 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 GPT-5.5 and GLM 5 Turbo?

ModelCap currently lists 3 API providers for GPT-5.5 and 1 for GLM 5 Turbo, from the OpenRouter catalogue snapshot the site serves; each model page lists the providers and their prices.

How current is this GPT-5.5 vs GLM 5 Turbo comparison?

Every figure comes from the sealed ModelCap dataset published 18 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.

Explore further