GPT-5.5 Pro vs GLM 5.2
Detailed technical comparison between GPT-5.5 Pro (OpenAI) and GLM 5.2 (Zhipu AI). Review live API token pricing, context window capabilities, time-to-first-token latency, and verified benchmark scores side-by-side.
Comparison Snapshot
GPT-5.5 Pro
1,050,000 tokensTie
Equal CapabilityTie
Equal SpeedGLM 5.2
$0.80 / MTokGPT-5.5 Pro
GPT-5.5 Pro is OpenAI’s high-capability model optimized for deep reasoning and accuracy on complex, high-stakes workloads. It features a 1M+ token context window (922K input, 128K output) with support for...
GLM 5.2
GLM 5.2 is a large-scale reasoning model from Z.ai. It supports text input and output with a 1M-token context window, and is suited for long-horizon agent workflows, project-level software engineering,...
Technical Specifications
🏆 = Superior Spec| Specification | GPT-5.5 Pro | GLM 5.2 |
|---|---|---|
| Provider | OpenAI | Zhipu AI |
| Context Window | 1,050,000 tokens🏆 | 1,048,576 tokens |
| Agent Suitability | 98/100 | N/A |
| Time to First Token (TTFT) | 450 ms | N/A |
| Deployment Model | managed api | managed api |
| Production Stability | beta | beta |
| API Available | Yes | Yes |
| Released Date | 2026-04-24 | 2026-06-16 |
API Pricing Comparison
Input Price per Million Tokens
GPT-5.5 Pro
$30.00
GLM 5.2
$0.80
Output Price per Million Tokens
GPT-5.5 Pro
$180.00
GLM 5.2
$2.52
💡 Cost Ratio: GLM 5.2 is 37.5x cheaper per input token than GPT-5.5 Pro.
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Benchmark Performance Metrics
Standardized Scores (0–100%)Scores show verified raw accuracy percentages across standardized AI evaluation suites. Higher bars indicate superior performance in that domain.
GPT-5.5 Pro Quirks & Gotchas
- ▸Best-in-class instruction following for complex agentic chains
- ▸Premium pricing — use GPT-5 for cost-sensitive workloads
GLM 5.2 Quirks & Gotchas
No developer gotchas reported.
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