LLM Comparison
Sonar Reasoning Pro vs Grok 4 Fast
Side-by-side specs, pricing & capabilities · Updated April 2026
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2/6 modelsSame tier:
S Sonar Reasoning Pro | ||
|---|---|---|
| Organization | Perplexity AI | |
| OpenTools Score | ||
| Family | Sonar | Grok |
| Status | Current | Current |
| Release Date | Mar 2025 | Sep 2025 |
| Context Window | 128K tokens | 2.0M tokens |
| Input Price | $2.00/M tokens | $0.20/M tokens |
| Output Price | $8.00/M tokens | $0.50/M tokens |
| Pricing Notes | — | Cache read: $0.0500/M tokens |
| Capabilities | textvisioncodeextended-thinking | textvisioncode |
| Max Output | — | 30K tokens |
| API Identifier | perplexity/sonar-reasoning-pro | x-ai/grok-4-fast |
| Benchmarks | ||
| MMLU | 83 | — |
| View Sonar Reasoning Pro | View Grok 4 Fast | |
Cost Calculator
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| Model | Input | Output | Total / mo | vs Best |
|---|---|---|---|---|
| Grok 4 FastCheapest | $0.20 | $0.25 | $0.45 | — |
| Sonar Reasoning Pro | $2.00 | $4.00 | $6.00 | +1233% |
Perplexity AI
Sonar Reasoning Pro
Sonar Reasoning Pro is a multimodal llm from Perplexity AI. Supports up to 128,000 token context window. Achieves 83.0% on MMLU. Available from $2.00/M input tokens.
xAI
Grok 4 Fast
Grok 4 Fast is a multimodal llm from xAI. Supports up to 2,000,000 token context window. Available from $0.20/M input tokens.
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