LLM Comparison
GPT-5.5 vs Grok 4.20
Side-by-side specs, pricing & capabilities · Updated April 2026
Price vs Intelligence
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2/6 modelsSame tier:
| Organization | ||
| OpenTools Score | 90 5.1 | 77 19.1 |
| Family | GPT | Grok |
| Status | Current | Current |
| Release Date | Apr 2026 | Mar 2026 |
| Context Window | 1.1M tokens | 2.0M tokens |
| Input Price | $5.00/M tokens | $2.00/M tokens |
| Output Price | $30.00/M tokens | $6.00/M tokens |
| Pricing Notes | Cached input: $0.50/M tokens. Long context (>272K tokens): 2x input, 1.5x output. Batch API: 50% discount. Priority: 2.5x standard. | Cache read: $0.2000/M tokens |
| Capabilities | textvisioncodetool-useextended-thinkingcomputer-useweb-search | textvisioncode |
| Training Cutoff | December 2025 | — |
| Max Output | 128K tokens | — |
| API Identifier | openai/gpt-5.5 | x-ai/grok-4.20 |
| Benchmarks | ||
| MMLU | 92.4openai | — |
| GPQA Diamond | 93.6openai | — |
| ARC-AGI-2 | 85openai | — |
| Terminal-Bench 2.0 | 82.7openai | — |
| SWE-bench Pro | 58.6openai | — |
| OSWorld-Verified | 78.7openai | — |
| BrowseComp | 84.4openai | — |
| MMMU-Pro | 81.2openai | — |
| FrontierMath Tier 4 | 35.4openai | — |
| HLE (with tools) | 52.2openai | — |
| GDPval | 84.9openai | — |
| Toolathlon | 55.6openai | — |
| CyberGym | 81.8openai | — |
| MRCR v2 512K-1M | 74openai | — |
| View GPT-5.5 | View Grok 4.20 | |
Cost Calculator
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| Model | Input | Output | Total / mo | vs Best |
|---|---|---|---|---|
| Grok 4.20Cheapest | $2.00 | $3.00 | $5.00 | — |
| GPT-5.5 | $5.00 | $15.00 | $20.00 | +300% |
OpenAI
GPT-5.5
GPT-5.5 is OpenAI's smartest and most intuitive model, built for agentic work like coding, research, and data analysis. It matches GPT-5.4 per-token latency while delivering higher intelligence with significantly fewer tokens. Supports a 1,050,000 token context window and five reasoning effort levels (none through xhigh).
xAI
Grok 4.20
Grok 4.20 is a multimodal llm from xAI. Supports up to 2,000,000 token context window. Available from $2.00/M input tokens.
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