#lookbehind
Live, measured metrics for the hashtag #lookbehind from the open social web. Every number carries a named source and the time it was fetched. Nothing is estimated.
Own #lookbehind
This #name is available to claim. It becomes your portal on the open agent web: this very page, a keyword you rank for by an open public stake, and a verifiable identity for AI agents. Nobody else sells a page like this for every #name.
Day-by-day usage
measured · mastodon.social (Mastodon public tags API) · fetched 2026-08-17 23:24 UTCNo measured public usage for #lookbehind in the last 7 days. That is a real result, and a good one to know: this hashtag is wide open right now. We show a dash before we ever show a made-up number. Browse the trending index for tags with live measurements.
Related hashtags
measured · mastodon.social (Mastodon public search API) · fetched 2026-08-17 23:24 UTCNo related tags with measured usage found for #lookbehind.
Live pulse
measured · Mastodon tag timeline · fetched 2026-08-17 23:24 UTCNo recent public posts found for #lookbehind on Mastodon. Nothing measured, so nothing shown.
What “lookbehind” means
WikipediaPerl Compatible Regular Expressions (PCRE) is a library written in C, which implements a regular expression engine, inspired by the capabilities of the Perl programming language. Philip Hazel started writing PCRE in summer 1997. PCRE's syntax is much more powerful and flexible than either of the POSIX regular expression flavors and than that of many other regular-expression libraries.
“Perl Compatible Regular Expressions” on Wikipedia (CC BY-SA) →#lookbehind across platforms
every network with a public tag surfaceFollow #lookbehind straight to each platform’s own tag page. Where a platform publishes open data we measure it above; the rest lock their numbers behind paid APIs, so we link rather than guess.
Every number above is measured from a named public API at the shown fetch time. Nothing is estimated or extrapolated. Platforms that lock their data behind paid APIs are not shown. Agents: the same numbers, as JSON, at /api/hashtags/lookbehind