This isn’t for the MusicBrainz site, but it helps me a lot especially as I try to add wikidata links to MB.
Wikipedia: Wikidata Links
On wikipedia in order to get to the wikidata links it’s not always easily accessible, sometimes you need to click on the toolbar etc, so I made myself a small script that gives me a nice button on top of each Wikipedia page with the wikidata link for the article I’m reading.
I am also a smartphone editor, thanks for all your guidance on that! (I am still using kiwi)
Added now support for the work editor, thanks for all the help @jesus2099 !
When recording lengths in a merge differ by 15 seconds or more they are highlighted in red.
Unfortunately this is only shown the merge has already been entered so I made a script to implement MBS-10966
Harmony is lacking a copy to clipboard feature and I got too lazy copying missing lengths by hand.
This script will extract them from the tracklist table and copies them to the clipboard once the length header is clicked.
@rinsuki made a userscript to lookup an ISRC on Spotify but seeing how people often used the SoundExchange database as a reference too I modified it a bit.
You can find the original script on GitHub:
Thanks chaban! Now you can share the rest as well 
This one I’ve initially made for myself to more quickly merge selected recordings but then extended it for other actions such as editing, removing and opening the artwork page.
The YouTube video importer was one of the scripts I was missing the most and while I was able to somehow make it work again it was lacking in features.
Most importantly it didn’t handle YouTube’s page navigation and didn’t check if a video was already in the database.
Thanks to @RustyNova for the initial revamp.
Update
It goes without saying that this script has privacy implications due to checking if a video (and YT channel) already exists in MusicBrainz meaning that MusicBrainz could build a history of which videos you watched and correlate it to your account based on IP addresses. (I’ve just pushed an update so API requests to MB no longer send cookies along 
)
This script is rather simple but can be very useful to more quickly spot duplicates in new edits.
On edit lists and pages it will check each barcode for presence in the database. If a match is found the barcode will be highlighted and a search link appended.
@chaban I am really enjoying this script you made!
This one is kind of a companion to the other barcode highlighting script except that it looks at release lists and edits.
Sets of duplicate barcodes are highlighted in the same color if formats are the also the same.
In edits this can make spotting subtle barcode differences easier and in release lists it will also select the merge checkboxes on click for easier merging. (Protip: Combine this with the hotkeys script)
Another modification of an existing script originally by @atj
It adds ISRC Hunt links to Spotify URLs on release pages for easier ISRC import but it was lacking support for Deezer URLs. Fret no more, it supports Deezer now.
I’ve heard some people wanted to be able to more easily get to the harmony import page for existing releases or something like that.
This script adds a re-lookup link on the Harmony release actions page.
I made a bookmarklet for Wikipedia category pages that checks which artists are already linked to MusicBrainz via Wikidata, and which are not yet.
It’s helpful if you’re working on adding artists from a specific location or category.
Tested on English and Hebrew Wikipedia, but it should work on any language version.
javascript:(()=>{fetch('https://raw.githubusercontent.com/YoGo9/Scripts/refs/heads/main/musicbrainz-checker-bookmarklet.js').then(r=>r.text()).then(eval);})()
Check that too (click “more info”): https://wiki.musicbrainz.org/External_Resources#Bookmarklets
If you were using the ISRC importer by @tatsumo (d.ontun.es) you might be missing the ISRC highlighting in ISRC Hunt.. I’ve tried to reimplement this as a userscript.
I’ve already linked it the other day but now as a more proper announcement. This script is based on “Bandcamp: Show publish date” by w-biggs aka @cigazze
It extracts slightly more dates and normalizes them to UTC. The original script might give different dates depending on your time zone
Also mentioned in ISRC Hunt’s thread the other day.
Since ISRC Hunt still uses fixed provider parameters I’ve tried making a script that rewrites the links to use your preferred providers.
A very tiny script whose sole purpose is to automatically click the “Show acoustIDs” button on artist’s recordings lists.
Needless to say it depends on @loujin’s script “Display acoustIDs and merge recordings with common acoustID”
Another script for the convenience of hardcore importers.
It will automatically click the button to confirm the form submission which occurs when submitting data to MusicBrainz from external sites (or Picard under certain circumstances)
A word of warning though:
These interstitial pages exist for security reasons against CSRF allowing you to inspect the data being submitted.
An alternative method to skip the confirmation page for importers is the skip_confirmation parameter (MBS-13225)
Concerning the “Auto login MusicBrainz ISRC importers” userscript already linked by @yomo12
This one will also potentially lower the security of your account.
Right now the script is basically only checking if the protocol and hostname of MagicISRC or ISRC Hunt are present in the URL.
A rogue website/application could gain access to parts of your data and edit rights by sticking either of them into to the redirect_uri parameter
Update
The ISRC importer login script should be more secure now. I’ve changed from using @include to @match directives so it only runs on the real MusicBrainz URLs (this change applies to the other scripts as well) and added more checks comparing the client_id plus redirect_uri and if the scopes are as expected.
Thanks @chaban!
It’s worth reiterating, in case newer members have missed it, that we have a community maintained list of userscripts here: Guides/Userscripts - MusicBrainz Wiki
It is a useful directory if you are looking for a specific script, or would just like to browse.
Even though this script is not quite finished yet it should already be useful for those poor souls slaving away at the dreaded reports. It will also hide reports which are empty.
See for yourself:
Not exactly what @salo.rock imagined I guess but a small consolation I hope.
