Omeka Classic, Omeka S Side-by-Side

Omeka Classic Omeka S
Hosting requirements Linux operating system; Apache HTTP server (with mod_rewrite enabled); MySQL version 5.0 or greater; PHP scripting language version 5.4 or higher (with mysqli and exif extensions installed); Imagemagick for file derivatives Linux operating system; Apache (with AllowOverride set to “All” and mod_rewrite enabled); MySQL 5.6.4+ (or MariaDB 10.0.5+); PHP 7.2+ (latest stable version preferred, with PDO, pdo_mysql, and xml extensions installed); Imagemagick (+6.7.5)
Core building block Item Item
Grouping Items Collections (each Item may only belong to a single Collection) Item Sets (Items may belong to an unlimited number of Item Sets)
Descriptive schema Dublin Core Metadata Initiative Terms and user editable descriptors for Item Type metadata Installs with DCMI Terms, DCMI Types, BIBO, and FOAF linked data vocabularies. Users can import other LOD vocabulary. Then, users can design Resource Templates with LOD Vocab properties to create a custom descriptive framework.
Data types Text or HTML Text, Omeka S Resource, URI are core and can be extended to include a range of numeric data types and controlled vocabularies
Media File upload via browser (bulk upload via CSVImport or Dropbox plugins) File upload via browser (bulk upload via CSVImport, File Sideload modules, Omeka2Importer, Fedora Connector, DSpace Connector), HTML, IIIF image, oEmbed
Permission levels Users - Omeka Classic User Manual User Permissions - Omeka S User Manual
Publication status Public/Private for Items, Collections, Pages, Exhibits Public/Private for Items, Item Sets, Sites, Pages
Multiple sites/Exhibits One site, with an unlimited number of exhibits (built using the Exhibit Builder plugin) Many sites are possible, but installation can also be set to a single site; no external Exhibit Builder module
Starter pages Browse Items, Browse Collections Welcome, and Custom link pages: Custom URL, Browse, Browse item sets, and others that are generated by modules
Page building method Within exhibits, pages are constructed from blocks Within sites, all pages are built with blocks
API Built-in Built-in, REST
Output formats omeka-xml, omeka-json, dcmes-xml, json, atom, rss JSON-LD