See the Zotero 9 announcement for more details.

• Read Aloud
  • Listen to PDFs, EPUBs, and webpage snapshots with high-quality, natural-sounding voices
  • Annotate the last sentence with a single click or H/U on keyboard
  • Last reading position is saved and synced across devices
  • Start reading from any paragraph by clicking in the left margin while Read Aloud is activated
• “Recently Read” collection
  • New virtual collection in each library showing items you've read recently, synced across devices
  • “Last Read” column available in all views
  • “Attachment Last Read” search condition
• Insert annotations directly into word processor documents
  • New “Add Annotation” button in word processor plugins lets you insert annotations directly into your document with active Zotero citations
• “Added By” and “Modified By” for group libraries
  • View the group members who added and/or last edited items
  • Shown in item pane, and can be added as columns in the items list
• Per-group file renaming settings
  • Group admins can configure file-renaming templates for each group library
• Performance improvements
  • Reduced startup memory usage by ~20%
  • Detect external local attachment changes during sync without scanning all files
  • Avoid repeated checks for remotely missing files during sync
  • [Mac] Use APFS cloning for file copies, including automatic database backups, to save potentially hundreds of megabytes or gigabytes of local disk space
• Web-based login flow
  • Log in to your Zotero account via the browser instead of entering credentials in the app
  • Allows use of password managers
  • Allows for two-factor authentication (currently testable; available by default soon)
• Improved RTF Scan
  • Support for citations with extended and non-Latin characters in authors and titles
  • Support for additional quotation mark styles
  • Support for citations with title but no author
  • Support for documents with multiple character encodings
• Reader changes
  • Improved theme handling for scanned PDFs
  • Support for fixed-layout EPUBs
  • Don't apply dark-mode styling to printed PDFs
• Items list improvements
  • “+”/“-” keys now expand/collapse all rows one level at a time
  • Added Director as fallback for Creator for Video Recording items
  • Fixed Title column not being recoverable when hidden by a plugin
• Added “Citation Key” column to items list
• Search by citation key in search bar (“Title, Creator, Year” mode) and citation dialog
• “View Online” button for PMID/PMCID to open PubMed and PubMed Central directly from the item pane
• Fixed “Rename File to Match Parent Item” button sometimes not appearing
• Don't merge trashed attachments
• Improved keyboard navigation in drop-down menus
• Exclude ©, ®, and ™ from emoji detection
• Show account email addresses in sync settings
• Various other improvements and bug fixes