SpaceXAI: Grok 4.5 vs Anthropic: Claude Sonnet 5
Side-by-side comparison of specs, pricing, benchmark scores, and task rankings. Updated 2026-10-08.
| SpaceXAI: Grok 4.5 | Anthropic: Claude Sonnet 5 | |
|---|---|---|
| Vendor | x-ai | anthropic |
| Quality Score | 100 | 100 |
| Benchmark Score | 65.0 | 63.9 |
| Input Price | $2.00/M | $2.00/M |
| Output Price | $6.00/M | $10.00/M |
| Context Window | 500,000 | 1,000,000 |
| Max Output | 450,000 | 128,000 |
| Tool Calling | ✓ | ✓ |
| Structured Output | ✓ | ✓ |
| Reasoning Mode | ✓ | ✓ |
| Vision | ✓ | ✓ |
| Audio | - | - |
| Benchmark Scores | ||
| ai_index | 64.0 | 63.0 |
The verdict
For a sample job of 1 million input tokens and 250,000 output tokens, Grok 4.5 costs $3.50 and Claude Sonnet 5 costs $4.50, so Grok 4.5 is about 1.3 times cheaper for the same work.
Claude Sonnet 5 reads up to 1,000,000 tokens at once, roughly 1,500 pages of text, against about 750 pages for Grok 4.5.
On our blended benchmark score Grok 4.5 leads 65.0 to 63.9.
Across the 18 tasks where they differ, Grok 4.5 scores higher on 18 (SQL Generation, Code Review, Code Completion and others).
Grok 4.5 was released in July 2026 and Claude Sonnet 5 in June 2026.
Pick Grok 4.5 if you need lower cost, benchmark performance or the stronger all-round task scores; pick Claude Sonnet 5 if you need long documents.
Costs use current list prices per million tokens; page counts assume about 0.75 words per token and 500 words per page.
Who wins by task?
| Task | SpaceXAI: Grok 4.5 | Anthropic: Claude Sonnet 5 |
|---|---|---|
| SQL Generation | 140 | 140 |
| Code Review | 144 | 144 |
| Code Completion | 119 | 118 |
| Code Refactoring | 146 | 146 |
| Bug Fixing | 148 | 148 |
| Unit Test Generation | 131 | 131 |
| Code Documentation | 136 | 135 |
| Regex Writing | 124 | 123 |
| CI/CD Pipelines | 127 | 127 |
| Frontend Component Design | 129 | 129 |
| Data Analysis | 133 | 133 |
| CSV / Spreadsheet Cleanup | 135 | 135 |
| ETL Scripting | 137 | 136 |
| JSON Extraction | 122 | 121 |
| Bulk Data Labeling | 119 | 118 |
| Long-Document Summarization | 147 | 146 |
| Short-Form Summarization | 117 | 116 |
| Blog Post Writing | 128 | 128 |
Scores reflect capability match + benchmark data + pricing for each task. Methodology →