Claude Sonnet 5 vs Claude Sonnet 4.6
Facts only. This page does not pick a winner. For a picked winner, see the use case comparison on Tools.
| Claude Sonnet 5 | Claude Sonnet 4.6 | |
|---|---|---|
| API model IDs | claude-sonnet-5 | claude-sonnet-4-6 |
| Context window | 1,000,000 | 1,000,000 |
| Lifecycle | active | legacy |
| License | proprietary | proprietary |
| Trains on API data | No | No |
| Zero data retention | on-request | on-request |
| Input per 1M tokens | $2 (verified 2026-09-08) | $3 (verified 2026-09-08) |
Frequently asked questions
- Which has the larger context window, Claude Sonnet 5 or Claude Sonnet 4.6?
- Claude Sonnet 5 holds 1,000,000 tokens and Claude Sonnet 4.6 holds 1,000,000. Both hold 1,000,000 tokens. The context window counts the prompt, any attached files, and the reply together.
- Which is cheaper, Claude Sonnet 5 or Claude Sonnet 4.6?
- Per million input tokens, Claude Sonnet 5 was $2 (verified 2026-09-08) and Claude Sonnet 4.6 was $3 (verified 2026-09-08). Claude Sonnet 5 is cheaper per input token. Output tokens cost $10 and $15 respectively, and output volume usually decides the bill.
- Does Claude Sonnet 5 or Claude Sonnet 4.6 train on API data?
- Claude Sonnet 5 does not train on API data by default, and Claude Sonnet 4.6 does not train on API data by default. Zero data retention is on-request for Claude Sonnet 5 and on-request for Claude Sonnet 4.6. Verified 2026-09-08 and 2026-09-08 against the providers' own documentation.
- Is Claude Sonnet 5 or Claude Sonnet 4.6 being retired?
- Claude Sonnet 5 is active. Claude Sonnet 4.6 is legacy. Lifecycle checked 2026-09-08 and 2026-09-08. Pin a dated snapshot ID rather than an alias if a retirement would break you.