thirtieth June 2026 – Hyperlink Weblog
What’s new in Claude Sonnet 5 (by way of) Claude Sonnet 5 got here out this morning. I at all times head straight for the “what’s new” developer docs as a result of they have a tendency to have extra actionable data than the official announcement put up.
Anthropic say of Sonnet 5 that “its efficiency is near that of Opus 4.8, however at decrease costs”. The system card helps clarify how they have been in a position to launch the mannequin with out being blocked by the US authorities:
Sonnet 5 is considerably much less succesful at cyber duties than Mythos 5: its safeguards are thus just like these we apply to Opus 4.7 and Opus 4.8 (fashions which can be extra succesful than Sonnet 5 however a lot much less succesful than Mythos 5).
Of word from the “what’s new” API adjustments:
Sampling parameters temperature, top_p, top_k are not supported.
It has a 1 million token context window and 128,000 most output tokens.
It options “the identical set of instruments and platform options as Claude Sonnet 4.6”
Adaptive considering is on by default, until you specify “considering”: {kind: “disabled”}.
The pricing is identical as Sonnet 4.6: $3/million enter, $15/million enter, with an introductory low cost to $2/$10 till thirty first August. However…
The mannequin has a brand new tokenizer, the place “The identical enter textual content produces roughly 30% extra tokens than on Claude Sonnet 4.6.” – successfully a 30% value improve.
I used my Claude Token Counter instrument to check out the brand new tokenizer. Listed below are my outcomes for a number of bigger paperwork:
Doc
Sonnet 4.6
Opus 4.7
Sonnet 5
Common Declaration of Human Rights (English)
2,356
3,3471.42x
3,3411.42x
Common Declaration of Human Rights (Spanish)
3,572
4,7531.33x
4,7471.33x
Common Declaration of Human Rights (Chinese language, Mandarin Simplified)
3,334
3,3661.01x
3,3601.01x
sqlite_utils/db.py (4,279 strains of Python)
44,014
56,1181.28x
56,1131.27x
So the brand new token is roughly 1.4x occasions costlier for English, 1.33x for Spanish, 1.28x for Python code and successfully the identical value for Simplified Mandarin.
This is the pelican. It is nothing to jot down dwelling about. Sonnet 5 thinks it appears to be like like a goose.
