Anthropic · Claude Opus 5 · July 2026

Claude Opus 5 — Anthropic’s strongest model for coding and agent work

  • Million-token context
  • Extra-long single replies
  • Deep thinking built in
  • Tunable depth tiers
Claude Opus 5

What is Claude Opus 5?

Claude Opus 5 is Anthropic’s Opus flagship, released in July 2026. It’s built for work you can’t half-finish: changing features in a large repo, hunting root causes, and driving tools step by step until the job is done. Deep thinking is built in; context and output are sized for long jobs; tune depth when you need more or less. Versus Claude Opus 4.8, long-horizon coding, multi-step tools, and knowledge work are steadier, with fewer half-finished patches. On iMini Agent, pick Claude Opus 5 to use it.

Vendor
Anthropic
Released
July 2026
Context
1M tokens
Max output
128K tokens
Deep thinking
On by design · tunable
Best as
Primary for long-horizon coding & agents

What’s new versus Claude Opus 4.8

Out-of-the-box behavior, long-horizon completion, context, and multi-step tools—the four changes to understand before making it your everyday primary.

Deep thinking on out of the box

Deep thinking is built in: it organizes constraints and a path before acting. Tune depth when you need more or less. Complex jobs see fewer “write first, discover problems later” failures.

Higher long-horizon coding completion

On cross-file features, large refactors, and root-cause work, it leaves fewer unfinished changes and fewer symptom-only fixes—better as an everyday engineering primary.

Steadier progress under long context

Long specs, multi-turn history, and tool traces can stay in one conversation. Large-repo changes and long migration plans don’t need to be fragmented early.

More complete multi-step tool workflows

On jobs that call tools repeatedly and finish end to end, it holds goals and abort conditions better—fewer mid-run drifts or half stops—suited as an Agent primary.

Official evaluations and alignment audits

Evaluations and alignment results Anthropic published with Claude Opus 5—covering software engineering, knowledge work, business automation, and behavioral audits.

Claude Opus 5 multi-task evaluation overview
Multi-task overview. Putting software engineering, knowledge work, business automation, and computer use on one board shows where Claude Opus 5 sits versus Claude Opus 4.8, Claude Fable 5, and peers—not a single score in isolation.
Frontier-Bench: agent coding performance by depth tier
Frontier-Bench focuses on agent coding. The chart shows how scores move with depth: Claude Opus 5 clearly beats Claude Opus 4.8, and it’s a core signal for long-horizon coding, terminal, and tool-collaboration work.
CursorBench: IDE coding performance by depth tier
CursorBench is closer to everyday IDE coding and agent collaboration. Scores vary by depth; at the top tier it approaches Claude Fable 5—useful when editing a repo and making multi-step changes inside an editor.
GDPval-AA: knowledge-work performance by depth tier
GDPval-AA measures real knowledge-work performance; the curve rises with depth. It covers research synthesis, table work, and numeric reasoning—watching whether Claude Opus 5 stays checkable under long materials and hard constraints.
AutomationBench: end-to-end business task pass rate
AutomationBench measures whether end-to-end business workflows finish. Claude Opus 5 sits near the front of the pack; even at lower depth it keeps high completion—an important reference for multi-step business agents.
ARC-AGI-3: novel problem-solving performance
ARC-AGI-3 tests solving under uncommon constraints and novel problems. Claude Opus 5 sits well above on-screen peers—still able to decompose and keep reasoning when no ready template exists.
Behavioral alignment audit: misalignment score
Behavioral alignment audits count deception, induced misuse, and related misalignment—lower is better. Claude Opus 5 scores 2.3, below recent same-family peers—a production-primary signal alongside capability scores.
OSS-Fuzz: vulnerability discovery vs exploit generation
OSS-Fuzz separates finding vulnerabilities from writing usable exploits. Claude Opus 5 is close to Mythos 5 on discovery but clearly weaker on exploit generation—keep those two measures separate in security workflows.

Three common workflows

Claude Opus 5 fits work that must keep moving and end with a deliverable result.

Repo changes & code review

For cross-file feature work, hard-to-reproduce bugs, and evidence-based PR review. The point isn’t a fast opinion—it’s clear root cause, blast radius, and verification so merges don’t bounce back.

Research synthesis & decision memos

For collapsing long materials into a one-page decision: the problem, options, recommendation, and risks. Suited to knowledge work with tables, numbers, and explicit constraints.

Multi-step agent jobs

For workflows that call tools repeatedly and advance step by step to a result. Agree inputs, done criteria, and stop conditions per step so the job can run end to end.

How to choose vs Claude Fable 5 and GPT-5.6 Sol

All three are current flagships. The differences are out-of-the-box depth, product stack, and which jobs you run most.

DimensionClaude Opus 5Claude Fable 5GPT-5.6 Sol
Context1M tokensTop Claude long-context tierOpenAI Sol flagship context
ReasoningDeep thinking built in, tunableTop of the Claude capability ladderOpenAI maximum-depth tier
Coding / agentsEveryday primary for long-horizon coding & multi-step agentsWhen you need top-of-Claude capabilityBetter when the team is bound to OpenAI’s depth stack
Long tool runsStronger goal holding and completionHeavier, top-tier agent scenariosAvailable on iMini Agent; stack leans OpenAI
Speed postureCompletion quality and stability firstHeavier; cost and latency usually higherMaximum depth first
Prefer whenNew long-horizon coding, multi-step agents, knowledge workTop-of-Claude capability and you can accept higher loadOrg standard is already OpenAI Sol

Using Claude Opus 5 on iMini

Free quota, model naming, key specs, and how it differs from Claude Fable 5 and GPT-5.6 Sol.

Use Claude Opus 5 free on iMini Agent

Million-token context, deep thinking built in, tunable depth tiers.

Open Claude Opus 5

No Anthropic API key required.