Anthropic shipped an upgraded Claude Opus 4.8 focused on coding, agentic tasks and long-running professional work — with two features that stand out: parallel subagents and a 2.5x fast mode.
What’s new
- Parallel subagents: Claude can spin off multiple sub-tasks at once and merge the results, speeding up complex jobs.
- Fast mode: up to 2.5x faster output without dropping to a smaller model.
- Benchmarks: 88.6% on SWE-bench Verified, 74.6% on Terminal-Bench 2.1, 1890 Elo on GDPval-AA.
- Consistency on long tasks: better at holding context across multi-hour agentic runs.
What this means for you
- If you use Claude for coding, parallel subagents cut wall-clock time on big refactors and multi-file changes.
- Fast mode is ideal when you’re iterating quickly and want responses now.
- For long autonomous tasks, the improved consistency means fewer “lost the thread” moments.
FAQ
Does fast mode use a weaker model? No — it’s the same Opus model with faster output.
What are subagents in practice? Independent helpers Claude launches to work on parts of a task in parallel, then combines.