Anthropic: Claude Sonnet 4.5 vs Grok 4 Fast
Grok 4 Fast is cheaper than Anthropic: Claude Sonnet 4.5 by about 95% on a blended (75% input / 25% output) basis. Anthropic: Claude Sonnet 4.5 charges $3.000000 / $15.000000 per 1M input/output tokens; Grok 4 Fast charges $0.200000 / $0.500000.
| Field | Anthropic: Claude Sonnet 4.5 | Grok 4 Fast |
|---|---|---|
| Input $/Mtok | $3.000000 | $0.200000 |
| Output $/Mtok | $15.000000 | $0.500000 |
| Cache read $/Mtok | $0.300000 | – |
| Cache write $/Mtok | $3.750000 | – |
| Input $/Mchar | n/a | n/a |
| Output $/Mchar | n/a | n/a |
| Context window | 1000000 | 2000000 |
| Tokenizer | claude | – |
Price history
Same workload, monthly cost
Illustrative monthly cost at 10M tokens/month, split per workload preset. Not a substitute for the calculator, which uses your own volume, cache and batch assumptions.
| Workload | Anthropic: Claude Sonnet 4.5 | Grok 4 Fast |
|---|---|---|
| Coding agent | $36.00 | $2.15 |
| RAG chat | $48.00 | $2.45 |
| Summarisation (batch) | $42.00 | $2.30 |
| Classification | $32.40 | $2.06 |
| Chat assistant | $78.00 | $3.20 |
| Content generation | $126.00 | $4.40 |
Cite this page
Anthropic: Claude Sonnet 4.5 vs Grok 4 Fast: $3.000000/$15.000000 vs $0.200000/$0.500000 per 1M tokens, as of 2026-10-04 (Token Barometer, https://tokenbarometer.com/compare/anthropic_claude-sonnet-4-5-vs-xai_grok-4-fast).
Anthropic: Claude Sonnet 4.5 page | Grok 4 Fast page | Open in calculator