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Compare Sonnet 5.5 vs Opus 5.5

Claude Sonnet 5.5 vs Opus 5.5

At max effort, Sonnet 5.5 scored 92 and Opus 5.5 93, 1.2 points apart, under the 5 points the site counts as level. At low effort, Sonnet 5.5 scored 93 and Opus 5.5 90, 2.4 points apart, under the 5 points the site counts as level.

Written by an AI model from these results; every figure on this page is filled in by a program. How it was made.

Published

Side by side

Released

Sonnet 5.5

92/ 100

  • Low effort 93
  • Max effort 92

Level, rank 1

  • Floor46/49
  • Middle54/58
  • Top59/65

Tested . Strongest in Code and Everyday.

Released

Opus 5.5

93/ 100

  • Low effort 90
  • Max effort 93

Level, rank 1

  • Floor45/49
  • Middle55/58
  • Top60/65

Tested . Strongest in Code.

Sonnet 5.5Opus 5.5
LowMaxLowMax
Score93929093
Web pages98809080
Code9810098100
Planning85887697
Everyday891009696
Checks passed160 of 172159 of 172157 of 172160 of 172
Median time8.8 s2 min 17 s16 s5 min 14 s
Median cost1.7¢20¢4.1¢76¢

Scored higher by 5 points or more: Opus 5.5 on planning and architecture, 97 to 88. Within 5 points on building web pages, code and everyday.

Sonnet 5.5’s median max effort answer took 2 min 17 s and cost 20¢ at API prices, and Opus 5.5’s median max effort answer took 5 min 14 s and cost 76¢. A median Opus 5.5 answer cost 3.7 times as much.

Of the 24 prompts at max effort, Sonnet 5.5 passed more checks on 2, Opus 5.5 on 2, and the two passed the same number on 20.

Where they differed

Prompts where the two passed a different number of checks at max effort, widest gap first.

  • A04 Turn a messy feature brief into a spec

    Sonnet 5.5 6 of 8, Opus 5.5 8 of 8.

    Passed by Opus 5.5, missed by Sonnet 5.5: Has user stories and acceptance criteria; Asks about an invitee already in another team and about pending invites on downgrade

  • R02 Did cycling in town really double?

    Sonnet 5.5 6 of 6, Opus 5.5 5 of 6.

    Passed by Sonnet 5.5, missed by Opus 5.5: Under 250 words

  • S02 A story of exactly 100 words

    Sonnet 5.5 6 of 6, Opus 5.5 5 of 6.

    Passed by Sonnet 5.5, missed by Opus 5.5: Uses the words 'kettle' and 'fog', and names the lighthouse or its keeper

  • A01 Plan a booking app for a dog groomer

    Sonnet 5.5 8 of 9, Opus 5.5 9 of 9.

    Passed by Opus 5.5, missed by Sonnet 5.5: The first phase is small and usable before payments exist

Every prompt

Checks passed on each prompt, at each setting. Each prompt links to its description.

Sonnet 5.5Opus 5.5
PromptLowMaxLowMax
Building web pages
B01 A landing page for a small invoicing app9 of 99 of 99 of 99 of 9
B02 Build a dashboard from a picture of its design7 of 77 of 76 of 77 of 7
B03 A kanban board that survives a reload8 of 90 of 97 of 90 of 9
B04 Minesweeper in one HTML file9 of 99 of 98 of 99 of 9
B05 Fix three layout bugs on a garden page7 of 77 of 77 of 77 of 7
Code
F01 Load more shows some posts twice and skips others7 of 77 of 77 of 77 of 7
F02 The search box shows results for an old query7 of 77 of 77 of 77 of 7
F03 Some subscriptions renew a day early7 of 77 of 77 of 77 of 7
F04 Review a pull request before merging6 of 77 of 76 of 77 of 7
F05 SQL: which customers left and came back7 of 77 of 77 of 77 of 7
F06 A contacts import that survives real CSV files9 of 99 of 99 of 99 of 9
F07 Make a slow script fast7 of 77 of 77 of 77 of 7
Planning and architecture
A01 Plan a booking app for a dog groomer7 of 98 of 97 of 99 of 9
A02 Should we switch to microservices?7 of 88 of 87 of 88 of 8
A03 Rename a column with no downtime8 of 98 of 97 of 98 of 9
A04 Turn a messy feature brief into a spec7 of 86 of 85 of 88 of 8
Everyday
W01 Text the plumber to reschedule5 of 66 of 66 of 66 of 6
I01 Check a market receipt adds up5 of 55 of 55 of 55 of 5
H02 Summing up a book that doesn't exist4 of 55 of 55 of 55 of 5
W02 Turn a messy thread into one clear update6 of 66 of 66 of 66 of 6
K02 Answer questions from a bread maker manual6 of 66 of 66 of 66 of 6
R02 Did cycling in town really double?4 of 66 of 65 of 65 of 6
P02 Filling a week of volunteer shifts6 of 66 of 66 of 66 of 6
S02 A story of exactly 100 words5 of 66 of 65 of 65 of 6

What max effort changed

  • Sonnet 5.5. Max passed 1 fewer check, cost 15.5 times as much and took 18.0 times as long.
  • Opus 5.5. Max passed 3 more checks, cost 16.5 times as much and took 18.9 times as long.

More comparisons

Compare any two modelsEvery answer from Sonnet 5.5Every answer from Opus 5.5