Claude Sonnet 4.5

legacy

Anthropic · Mid

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Previous Sonnet generation. Same $3 / $15 pricing as 4.6 — Sonnet pricing has held flat.

Strengths
Capable mid-tier Sonnet at the durable Sonnet price.
Best for
General-purpose work where the newest Sonnet isn't essential.
Limitations
Superseded by Sonnet 4.6 at identical pricing.

Input / 1M

$3.00

Output / 1M

$15.00

Cached input / 1M

$0.3

Context window

1M

Where it sits

250th-cheapest mid model

by blended $/Mtok among 262 listed mid models

950% above the mid median

blended $/Mtok across 262 mid models

Output costs 5× input

$3.00 in / $15.00 out per 1M

Cached input saves 90%

$0.3 vs $3.00 per 1M fresh

Held flat since launch (Sep 2025)

no blended price change recorded

Computed live from current prices and this model's history — not hand-written, so it stays accurate as prices move.

Price history

Only one price on record so far — the history chart appears once a price changes.

Snapshots

Effective Input Output Cached in Note Source
29 Sep 2025 $3.00 $15.00 $0.3 anthropic.com/pricing

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