Quick DuelLarge Codebase / Flagship checkmeth_v0_1_1 · peer min-max

Opus vs Sonnet

Flagship ceiling vs daily driver inside Anthropic — when upgrading is worth it. Public stats are peer-relative ranks (40–95 band among scored Builds), not absolute “% intelligence.”

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Build A

Claude Opus 4.8 · API · High effort (default)

The expensive architect — pays for hard repos, long agents, and fewer retries.

66.9

$5/$25 · claude-opus-4-8

Full sheet →

Build B

Claude Sonnet 5 · API · High effort (default)

A polished code smith with expensive habits — still the sensible daily driver.

50.8

$2/$10 · claude-sonnet-5

Full sheet →

Stat comparison

Six attributes (peer public)

Opus

Attr

Sonnet

77.5 A

STR

Execution

Opus +37.5

40.0 A

47.3 B

DEX

Tempo

Sonnet +14.2

61.5 A

76.0 A

CON

Reliability

Opus +36.0

40.0 A

84.5 A

INT

Reasoning

Opus +44.3

40.2 A

75.7 A

WIS

Judgment

Opus +22.7

53.0 A

40.1 A

CHA

Collaboration

Sonnet +30.1

70.2 A

Evidence beyond peer ranks

Same-harness & loadout

Signal	Opus	Sonnet
Vals SWE Verified · mini-swe-agent	88.6%	79.6%
Arena Elo (Thinking)	1506	1485
List price (in/out)	$5 / $25	$2–3 / $10–15

Quest verdicts

Large Existing Codebase

Decisive on Execution: Opus — public ranges do not overlap (Opus 73.5–81.5 vs Sonnet 36–44).

Large Existing CodebaseOpus · conf A
Clear independent SWE gap; peer STR also favors Opus over Sonnet.
Quest Fit →
Vibe Code a New AppSonnet · conf B
Quality close enough; price and tempo favor the daily driver.
Quest Fit →
Fast EverydaySonnet · conf A
DEX + cost inside the Claude family.
Quest Fit →
Under BudgetSonnet · conf A
Hard price filter vs Opus.
Quest Fit →

Opus: Pays for hard repos, long agents, and verification when wrong is expensive.

Sonnet: Default professional coding partner — elite enough most days without flagship burn.