Search Console regex tester and builder

How it works

Google's help says Search Console reads regex with the RE2 syntax. This page runs re2js, a JavaScript version of RE2, with the same defaults as Search Console: a pattern can match anywhere in a search unless you use ^ (starts with) or $ (ends with), and capitals are ignored unless you add (?-i).

Before you copy anything, the page checks the pattern for mistakes we see often and explains them in plain English:

• Patterns RE2 cannot run. Look-ahead such as (?!, look-behind and back-references are not supported. In a live Search Console check on 21 October 2026, a look-ahead pattern such as boiler(?!cover) was accepted without a warning and then showed no data, so a broken pattern looks just like a filter nobody searched for.
• Spaces next to |. They count as characters. In the same check, a two-search pattern written as (first search | second search) returned no rows, and the same pattern without the spaces returned both searches.
• \b next to £ or accented letters. RE2's word edge only understands A to Z, 0 to 9 and _, so \bcafé\b misses "café near me". Use \bcaf[eé] or £\d+.
• Page patterns that start with ^/. Page values are full addresses starting https://, so in the same check ^/blog/ showed no data and /blog/ worked.
• Length. The regex box in Search Console accepts up to 4,096 characters (checked 21 Oct 2026). The counter warns from 3,500.

Where to paste it

1. Open the Performance report for search results.
2. Click + Add filter and choose Query, or Page for addresses.
3. In the first menu choose Custom (regex).
4. Leave Matches regex, or choose Doesn't match regex to hide what the pattern catches.
5. Paste into the box labelled "Enter regular expression (regex)" and click Apply.

You can have one Query filter at a time, alongside a Page filter. If a long list goes over the limit, the builder can split it into two patterns: run each as its own view. With a filter on, Search Console notes that chart totals and table results might be partial, because filtered views leave out anonymised queries. Filtered numbers will not add up to the unfiltered total.

Testing somewhere else

The link to regex101 opens its Golang flavour, because Go uses RE2 syntax. regex101 has no flavour called RE2, and Golang there is case-sensitive by default, so check the i flag is on. A tester built on the browser's own JavaScript regex is not a safe check: it accepts look-arounds that Search Console will not run.

Your data

Your file is read in your browser. This page is set up to block outgoing connections, and we don't store your data. Share links keep the pattern and builder settings in the part of the address after #, which browsers do not send to the server, and they never include your test lines.