# Claude Opus 4.6

> **TL;DR.** [Claude Opus 4.

- **Category:** AI / Frontier Models / LLMs
- **Stage:** rising
- **Age:** 131 days
- **Origin date:** 2026-02-05
- **First detected:** 2026-04-21
- **Canonical URL:** https://earlyterms.com/term/claude-opus-4-6
- **Sources:** 9 primary URLs

## Definition

[Claude Opus 4.6](https://www.anthropic.com/news/claude-opus-4-6) is Anthropic's flagship LLM released February 5, 2026. It was the first Opus-class model with a 1M-token context window (beta at launch, now standard), shipped with unchanged $5/$25-per-million pricing, and introduced `agent teams` — a Claude Code preview letting multiple sub-agents parallelize a task.

4.6 scored 80.8% on SWE-bench Verified, 53.4% on SWE-bench Pro, and 76% on 8-needle 1M-MRCR (vs Sonnet 4.5's 18.5%). It reigned as Anthropic's most capable model for ~10 weeks before [Opus 4.7](https://www.anthropic.com/news/claude-opus-4-7) replaced it on April 16, 2026, and is still the default on paths where 4.7's 1.35x tokenizer inflation is a blocker.

## Example

GitHub Copilot Pro+ quietly routes agentic coding tasks to Opus 4.6 because, as one `r/github` thread documents, Pro+ users currently cannot select 4.7 at all — an artifact of pricing negotiations, not capability. Enterprise teams cite the same reason: 4.7 is 1.35x more expensive in practice at the same nominal rate.

## Analogy

The reigning champion three months into their title defense — still strong, but you can see the challenger's shadow in the ring.

## Why it's emerging now

Opus 4.6 is the unusual case of a superseded flagship that refuses to fade. 4.7's launch was hobbled by a 1.35x-tokenizer cost surprise; GitHub Copilot Pro+ locked out 4.7; and a well-documented 4.6 regression saga (Feb-Mar 2026) is still shaping how teams set `effort`. That keeps 4.6 on production rosters and in SERPs.

## Related terms

- *parent:* Claude
- *child:* Claude Opus 4.7
- *related:* Claude Opus 4.5
- *related:* Claude Sonnet 4.6
- *competitor:* GPT-5.2
- *competitor:* Gemini 3.0 Pro
- *related:* Claude Code
- *related:* Claude Agent SDK
- *related:* Managed Agents
- *related:* Agent Harness
- *related:* Context Window
- *related:* Claude Mythos

## Sources

1. [Anthropic — Introducing Claude Opus 4.6](https://www.anthropic.com/news/claude-opus-4-6)
2. [TechCrunch — Anthropic releases Opus 4.6 with new 'agent teams'](https://techcrunch.com/2026/02/05/anthropic-releases-opus-4-6-with-new-agent-teams/)
3. [AWS Bedrock — Claude Opus 4.6 model card](https://docs.aws.amazon.com/bedrock/latest/userguide/model-card-anthropic-claude-opus-4-6.html)
4. [TechFundingNews — Crushes benchmarks with 1M-token beta window](https://techfundingnews.com/anthropic-claude-opus-4-6-1m-context-coding/)
5. [llm-stats.com — Opus 4.7 vs Opus 4.6 benchmark comparison](https://llm-stats.com/blog/research/claude-opus-4-7-vs-opus-4-6)
6. [dgtldept — Opus 4.6 regression timeline and fixes](https://dgtldept.substack.com/p/claude-opus-4-6-actually-did-get-dumber-regression-fixes)
7. [Hacker News launch discussion (2,346 points)](https://news.ycombinator.com/item?id=46902223)
8. [Simon Willison — System prompt diff between 4.6 and 4.7](https://simonwillison.net/2026/Apr/18/opus-system-prompt/)
9. [Anthropic — Advancing finance with Opus 4.6](https://claude.com/blog/opus-4-6-finance)

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_Generated by EarlyTerms · https://earlyterms.com/term/claude-opus-4-6_