LLM Comparison
Grok 4.20 vs GPT-5.5 Pro
Side-by-side specs, pricing & capabilities · Updated May 2026
Price vs Intelligence
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2/6 modelsSame tier:
| Organization | ||
| OpenTools Score | 77 19.1 | 97 0.9 |
| Family | Grok | GPT |
| Status | Current | Current |
| Release Date | Mar 2026 | Apr 2026 |
| Context Window | 2.0M tokens | 1.1M tokens |
| Input Price | $2.00/M tokens | $30.00/M tokens |
| Output Price | $6.00/M tokens | $180.00/M tokens |
| Pricing Notes | Cache read: $0.2000/M tokens | No cached input discount. Long context (>272K tokens): 2x input, 1.5x output. Batch API: 50% discount. Regional processing: 10% uplift. |
| Capabilities | textvisioncode | textvisioncodetool-useextended-thinkingweb-search |
| Training Cutoff | — | December 2025 |
| Max Output | — | 128K tokens |
| API Identifier | x-ai/grok-4.20 | openai/gpt-5.5-pro |
| Benchmarks | ||
| FrontierMath Tier 4 | — | 39.6openai |
| FrontierMath Tier 1-3 | — | 52.4openai |
| HLE (with tools) | — | 57.2openai |
| HLE (no tools) | — | 43.1openai |
| BrowseComp | — | 90.1openai |
| GeneBench | — | 33.2openai |
| GDPval | — | 82.3openai |
| Investment Banking Modeling | — | 88.6openai |
| View Grok 4.20 | View GPT-5.5 Pro | |
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| Model | Input | Output | Total / mo | vs Best |
|---|---|---|---|---|
| Grok 4.20Cheapest | $2.00 | $3.00 | $5.00 | — |
| GPT-5.5 Pro | $30.00 | $90.00 | $120.00 | +2300% |
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.
OpenAI
GPT-5.5 Pro
GPT-5.5 Pro uses more compute to think harder and provide consistently better answers than GPT-5.5. Designed for the toughest problems, some requests may take several minutes. It excels at FrontierMath Tier 4 (39.6%) and BrowseComp (90.1%), offering the highest intelligence available from OpenAI at a premium price point.
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