xattred, Metamer, Sandstrip & xattr tools

xattred – full-featured extended attribute editor, can also add quarantine xattrs

xattred126
xattred lets you inspect and edit all extended attributes (xattrs) associated with a file or folder, cut/copy/paste any xattr between files or folders, create your own new xattrs with arbitrary contents, and add a quarantine xattr to force a full Gatekeeper check without downloading the file. Also has a crawler to explore types, sizes, and content of xattrs. Now supports adding and stripping xattr tags to control their preservation, and valuable interface improvements.
xattred 1.2 (Intel only for El Capitan, Sierra, High Sierra, Mojave, Catalina and Big Sur)
xattred 1.3 (Universal App for El Capitan, Sierra, High Sierra, Mojave, Catalina and Big Sur)

Metamer – accessible metadata editor for 16 Spotlight keys

metamer01
New! Metamer gives you full access to 16 of the most useful types of metadata which can then be used in Spotlight searches and more. No knowledge of extended attributes needed. Can also edit other text-based extended attributes if you wish.
Metamer 1.0 (Intel-only for El Capitan, Sierra, High Sierra, Mojave and Catalina)
Metamer 1.1 (Universal App for El Capitan, Sierra, High Sierra, Mojave, Catalina and Big Sur)

Pratique – simple utility to mark document quarantine flags as clear

pratique02
Pratique changes quarantine flags attached to documents so that they don’t cause a security error when set to open with an app other than the default. It doesn’t change those attached to apps, bundles, or archives, so that normal app security checks can still be carried out on those. This provides a more lasting way of preventing repeated security errors and refusal to open these documents. An alternative to Sandstrip. Now a Universal App and compatible with Big Sur.
Pratique 1.1 (Intel-only for Sierra, High Sierra, Mojave and Catalina)
Pratique 1.2 (Universal App for Sierra, High Sierra, Mojave, Catalina and Big Sur)

Sandstrip – simple utility to remove spurious extended attributes

sandstrip02
Sandstrip searches folders for spurious quarantine flags which have been attached to files by sandboxed apps, and removes them. Ideal when you encounter problems caused by these flags, such as in shell scripts which refuse to run, or documents which can’t be opened because of weird security errors. Doesn’t affect regular quarantine flags. Quick, and notarized for Mojave. An alternative to Pratique. Now a Universal App and compatible with Big Sur.
Sandstrip 1.1 (Intel-only for Sierra, High Sierra, Mojave and Catalina)
Sandstrip 1.2 (Universal App for Sierra, High Sierra, Mojave, Catalina and Big Sur)

SearchKey – adds metadata to any file to aid Spotlight search

searchkey31
SearchKey adds and edits five extended attributes which can be attached to any file (or folder), including creator, copyright, and keywords. These act as sticky markers, and are preserved in almost all file systems and iCloud Drive. They are indexed by Spotlight, and directly accessible in search criteria. Has single-file and batch modes to make life quick, simple, and search-perfect. New update with code integrity check and compatibility with Catalina.
SearchKey 1.3 (Intel-only for El Capitan, Sierra, High Sierra, Mojave and Catalina)
SearchKey 1.4 (Universal App for El Capitan, Sierra, High Sierra, Mojave, Catalina and Big Sur)

SearchKeyLite – lightweight tool to add metadata to documents to aid Spotlight search

searchkeylite01
SearchKeyLite provides a sleeker interface to similar features to those in SearchKey. This supports file drag-and-drop, can copy and paste all the metadata in single commands, and makes it even simpler to tag files with copyright information, etc. It lacks a batch mode, and cannot work inside bundles such as Photos Library, though. New update with code integrity check and compatibility with Catalina.
SearchKeyLite 1.3 (Intel-only for El Capitan, Sierra, High Sierra, Mojave and Catalina)
SearchKeyLite 1.4 (Universal App for El Capitan, Sierra, High Sierra, Mojave, Catalina and Big Sur)

cmpxat – a command tool to compare all the extended attributes (xattrs) between two files, reporting any differences

cmpxat is to extended attributes what cmp is for data in files: it compares them between two files, and reports all differences that it finds.
cmpxat 2 (Intel-only for El Capitan to Catalina)
cmpxat 3 (Universal App for El Capitan to Big Sur)

xattred & Metamer:

How WordPress comments and Property Lists can trip you up

Metamer version 1.1 is now a Universal App
xattred version 1.3 is now a Universal App
Metadata editing made easy with Metamer version 1
Major improvements in extended attribute editor xattred 1.2
Which extended attributes does iCloud preserve, and which get stripped?
Opening documents, SIP and quarantine flags in Catalina
How to save file metadata in iCloud, and new info on extended attributes
How to save your file metadata – implementation isn’t simple
How do the Finder, Terminal and Spotlight handle extended attribute flags?
xattred the GUI extended attribute editor reaches version 1.0 at last

SearchKey and SearchKeyLite versions 1.4 are Universal Apps
cmpxat, a command tool to compare extended attributes, now a Universal binary

Pratique & Sandstrip:

Quarantined documents, Pratique and Sandstrip
Sandstrip version 1.2 is now a Universal App
Pratique version 1.2 is now a Universal App
Tools updated to fix security errors when opening documents
Finder security errors opening documents: a summary
An alternative approach to document quarantine problems: Pratique
Sandstrip tackles your document quarantine problems
🎗 Quarantine: Apps
🎗 Quarantine: Documents
Sandstrip removes spurious quarantine flags

How to tag documents with metadata that works in search