JMGallery is two plugins. The free one does the work; the Pro add-on sits beside it and adds to it. Install the free plugin first.

JMarzTech Galleryversion 3.14.0 · freeLibrary, fields, bulk editing,displays, shortcodes, archive,CSV exportJMGallery Proversion 1.6.0 · add-onVideo, watermarking, 4 more fieldtypes, styling, downloads, selling,CSV import, Elementor widgetPro reads the free plugin’s hooks. On its own it renders nothing.
Pro is an add-on, not a replacement. Both plugins stay installed and active.

The free plugin

  1. In WordPress, go to Plugins › Add New › Upload Plugin and choose jmarztech-gallery.zip. If you are installing from the WordPress plugin directory, search for JMarzTech Gallery instead.
  2. Click Install Now, then Activate.
  3. A new JMGallery item appears in the admin menu.

On first activation the plugin creates six starter fields — Location, People, Album, Year, Date taken and Tags — and registers the archive and item URLs (/photos/ and /gallery-item/). Nothing else changes. Your Media Library is untouched.

The Pro add-on

  1. Download jmarztech-gallery-pro.zip from your account at jmarztech.com.
  2. Upload and activate it the same way. Leave the free plugin active.
  3. Activate your licence when Pro asks. See Licences and updates.

Pro 1.7.0 needs JMarzTech Gallery 3.15.0 or newer. If the free plugin is missing, older than Pro expects, or installed in a folder with a different name, Pro says so on every admin screen and tells you the exact fix rather than failing quietly.

On its first admin page load Pro adds four fields — Notes, Free download, Price and Buy link — unless your site already has fields with those keys. Delete any you do not want.

Requirements

WordPress6.2 or newer
PHP7.2 or newer. 8.2 is a better idea.
ThemesClassic and block themes both work.
Elementor3.5 or newer, only if you want the Pro widget.
PHP GDNeeded for watermarking, with JPEG, PNG and WebP support. Almost every host has it.

If you are uploading large photos, ask your host for upload_max_filesize 64M, memory_limit 256M and max_execution_time 300. Shared hosting defaults are often lower than that and the upload queue will tell you so.

After installing, visit Settings › Permalinks and click Save once. It costs nothing and it prevents the one 404 everybody hits.

Removing it

Deactivating either plugin deletes nothing. Deleting the free plugin also deletes nothing, unless you first switch on Delete all gallery data when this plugin is deleted in Settings. Your image files in the Media Library are never touched either way.