Claude Opus 5.5 vs GPT-5.6 Sol

$1.34 / task
Wins 10 of 22 benchmarks
$0.50 / task
Wins 1 of 22 benchmarks
AutomationBench-AA AutomationBench-AA: Agents orchestrate SaaS workflows through APIs; objectives receive credit only when the task has no guardrail violation
Opus 5.561.2
GPT-5.6 Sol51.3
GDPval-AA (work tasks) 2.1 GDPval-AA (work tasks) 2.1: Real work tasks from many professions (reports, spreadsheets, analyses), graded against expert work
Opus 5.554.2
GPT-5.6 Sol46.1
AA Analyst Agent AA Analyst Agent: Data-analyst tasks: the model explores data with tools and reports findings
Opus 5.5 · max56.3
GPT-5.6 Sol · max47.5
ITBench SRE ITBench SRE: IT incident tasks: diagnose and fix broken systems like a site-reliability engineer
Opus 5.5 · max38.2
GPT-5.6 Sol · max56.2
Terminal-Bench 4.0 Terminal-Bench 4.0 · source setting 2: Agents use a terminal to complete executable coding, system administration and research tasks in the 4.0 suite
Opus 5.552.5
GPT-5.6 Sol14.6
Terminal-Bench Science 0.1 Terminal-Bench Science 0.1: Agents complete expert-authored research workflows across five scientific domains in a terminal
Opus 5.543.3
GPT-5.6 Sol · max22.4
AA-Briefcase 1.1 · Elo AA-Briefcase 1.1 · Elo: Agents produce professional deliverables; blind pairwise comparisons produce the source Elo rating
Opus 5.51,625.1
GPT-5.6 Sol1,241.9
AA-LCR (long context) 1.1 AA-LCR (long context) 1.1: Questions that need reading and connecting facts across very long documents (around 100K tokens)
Opus 5.584.3
GPT-5.6 Sol80.3
DeepSWE 1.1 DeepSWE 1.1: Agents change repository code to resolve software engineering tasks under the stated DeepSWE edition
Opus 5.5 · max72.3
GPT-5.6 Sol61.1
EBR Bench EBR Bench: Agents learn to play Earthborne Rangers across repeated playthroughs
Opus 5.5 · max71.4
GPT-5.6 Sol · max44.8
Furniture Assembly Furniture Assembly: Models inspect furniture assembly photos, identify incorrect builds and locate the mistaken step
Opus 5.5 · max83.3
GPT-5.6 Sol · max56.7
τ³-bench · banking · 1.0.1 τ-bench official · 3-banking-1.0.1: Customer-service agents converse with simulated users, retrieve domain knowledge and change state through tools
Opus 5.5—
GPT-5.6 Sol · xhigh46.9
τ³-Banking · AA τ³-Banking · AA: Agents retrieve banking knowledge and execute tools to resolve customer-support workflows
Opus 5.5—
GPT-5.6 Sol36.5
Terminal-Bench Hard (version unstated) Terminal-Bench Hard (version unstated): Agents solve difficult software, system-administration and data-processing tasks in a terminal
Opus 5.5—
GPT-5.6 Sol62.9
EnterpriseOps-Gym-AA EnterpriseOps-Gym-AA: Agents complete stateful enterprise workflows in eight domains; final database state determines success
Opus 5.5—
GPT-5.6 Sol · max42.9
FrontierCode 1.1 FrontierCode 1.1: Agents implement changes in real repositories, graded against maintainer-defined requirements
Opus 5.557.1
GPT-5.6 Sol—
Harvey LAB-AA 1.1 Harvey LAB-AA 1.1: Legal agents work from case documents; every rubric criterion must pass and material hallucinations receive no credit
Opus 5.5 · max4.2
GPT-5.6 Sol—
SWE-bench Pro (v2 full) SWE-bench Pro (v2 full): Agents resolve repository issues under the network-locked v2 protocol; full and 51-task Hard results are separate
Opus 5.5—
GPT-5.6 Sol · xhigh95.5
SWE-bench Pro (v2 hard) SWE-bench Pro (v2 hard): Agents resolve repository issues under the network-locked v2 protocol; full and 51-task Hard results are separate
Opus 5.5—
GPT-5.6 Sol · xhigh82.4
SpireClimb SpireClimb: Agents play Slay the Spire under the named game and difficulty setting
Opus 5.5 · max3.3
GPT-5.6 Sol—
SpireClimb StS1 A20 Heart SpireClimb StS1 A20 Heart: Agents play Slay the Spire under the named game and difficulty setting
Opus 5.5 · max0
GPT-5.6 Sol—
SpireClimb StS2 A10 SpireClimb StS2 A10: Agents play Slay the Spire under the named game and difficulty setting
Opus 5.5 · max6.7
GPT-5.6 Sol—

Specs

SpecOpus 5.5GPT-5.6 Sol
Input, per 1M$4$4
Output, per 1M$20$20
Cost per task?$1.34$0.50
Speed, tok/s8185
Context1M1.05M
WeightsClosedClosed
ReleasedSep 2026Jul 2026
See images✓✓
Read PDFs✓Partial
Hear audio——
Watch video——
Call tools✓✓
Force a tool call—Partial
Return strict JSON✓✓
Search the web✓?
Run code✓?
Use a computer✓?

What breaks when you switch

Opus 5.5 → GPT-5.6 Sol
Nothing known.
GPT-5.6 Sol → Opus 5.5
Context: 1.05M → 1M
No forced tool use›

Forced tool_choice any or tool returns HTTP 400; remove the forced choice.

Thinking is always on›

Disabled thinking or a manual budget returns HTTP 400; omit thinking or use adaptive thinking.

Remove sampling parameters›

Non-default temperature, top_p or top_k returns HTTP 400; omit these parameters and use prompting.

No assistant prefill›

Assistant prefill returns HTTP 400; use structured outputs or system instructions, with system instructions on Bedrock.

Old computer tool rejected · Claude API / Google Cloud›

The computer_20251124 tool returns HTTP 400 on the Claude API and Google Cloud; use computer_toolset_20260801 there.

Return thinking blocks unmodified›

Edited, reordered or partially dropped thinking blocks return HTTP 400; echo assistant messages complete and unmodified with tool results.