Claude Sonnet 4.6 vs. Claude Sonnet 4.5: API Cost Comparison
On this API, Claude Sonnet 4.6 costs $1.5 / $7.5 per 1M tokens (in/out) and Claude Sonnet 4.5 costs $1.5 / $7.5. Claude Sonnet 4.6 is the cheaper option, and both run on the same key — switching is a one-line model parameter change.
Per-token pricing
| Claude Sonnet 4.6 | Claude Sonnet 4.5 | |
|---|---|---|
| Vendor | Anthropic | Anthropic |
| Input · per 1M tokens · Official list | $3 | $3 |
| Input · per 1M tokens · Your price | $1.5 | $1.5 |
| Output · per 1M tokens · Official list | $15 | $15 |
| Output · per 1M tokens · Your price | $7.5 | $7.5 |
| Discount vs. list | -50% | -50% |
| Context window | 200K tokens | 200K tokens |
| Max output tokens | 64K tokens | 64K tokens |
All prices in USD per 1M tokens.
What a real workload costs
Same request stream priced on both models — 10M input + 2M output tokens per month, a typical coding-agent load:
Claude Sonnet 4.6
- At official list
- $60 per month
- On this API
- $30 per month
Claude Sonnet 4.5
- At official list
- $60 per month
- On this API
- $30 per month
Switching between them
Both models answer on the same endpoint. Keep your base URL and key; change only the model parameter to reroute a request:
curl https://kktt.net/v1/chat/completions \
-H "Authorization: Bearer $API_KEY" \
-d '{"model": "claude-sonnet-4-6", "messages": [...]}'curl https://kktt.net/v1/chat/completions \
-H "Authorization: Bearer $API_KEY" \
-d '{"model": "claude-sonnet-4-5", "messages": [...]}'FAQ
Which is cheaper, Claude Sonnet 4.6 or Claude Sonnet 4.5?
On this API, Claude Sonnet 4.6 is cheaper: $1.5 in / $7.5 out per 1M tokens, versus $1.5 in / $7.5 out for Claude Sonnet 4.5.
Can I use Claude Sonnet 4.6 and Claude Sonnet 4.5 with the same API key?
Yes. Both are callable with one key on the same base URL — switching between them is a one-line change of the model parameter, which makes A/B testing or fallback routing trivial.
Do Claude Sonnet 4.6 and Claude Sonnet 4.5 differ in context window?
Claude Sonnet 4.6 supports 200K of context with 64K max output; Claude Sonnet 4.5 supports 200K with 64K max output.