Speed up responses with fast mode changedfast-mode
Nearest release: v2.1.304, published an hour after upstream edited the page. Shown because the two are within 24 hours of each other. Nothing here says the release caused the edit.
Upstream edited this page at 19 Oct 2026 18:23 UTC, give or take a minute or two: the time comes from Anthropic’s own sitemap rather than from a commit. This site recorded the change at 19 Oct 2026 18:37 UTC.
Upstream edited
Recorded here
Lines+1added
Lines−1removed
From line
41
where the diff opens
First seen
14 Aug 2026
this site's first read of the page
Recorded edits17to this page, all time
The whole hunk
from line 41, old and new numbered
/
from line 41
4141* A small `↯` icon appears next to the prompt while fast mode is active
4242* Run `/fast` again at any time to check whether fast mode is on or off
4343
44Opus 5.5 is the fast mode default in Claude Code v2.1.280 and later. Before v2.1.280, fast mode defaulted to Opus 5 from v2.1.219, to Opus 4.8 on v2.1.154 through v2.1.218, and to Opus 4.7 on v2.1.142 through v2.1.153.
44Opus 5.5 is the fast mode default in Claude Code v2.1.280 and later. Before v2.1.280, fast mode defaulted to Opus 5 from v2.1.219, and to Opus 4.8 on v2.1.154 through v2.1.218.
4545
4646When you disable fast mode with `/fast` again, you remain on Opus. To switch to a different model, use `/model`.
4747
No line in this hunk matches that.