Sonnet 5.5 costs 77% to 78% less than Sonnet 5 from low to high effort
Cost per task at list prices, 13 single-shot tasks, 3 repeats, 38 or 39 calls per bar.
Accuracy was 97% or better in every bar.
Claude Sonnet 5.5
Claude Opus 5.5
Claude Sonnet 5
$0.000
$0.005
$0.010
$0.015
$0.020
$0.025
4.1
7.0
21.2
default
4.3
6.5
18.4
low
4.0
8.2
18.0
medium
4.3
8.8
18.8
high
5.9
10.5
20.2
xhigh
14.6
23.4
19.3
max
Bar labels are cost per 1,000 tasks in dollars.
With no effort set, both Sonnets run at high and Opus 5.5 at medium.
Measured 2026-09-29 on the Anthropic Messages API.