Compare software

Trinka vs Harper: catalog facts
Trinka	Harper
Freemium Free to start, with paid plans including a Confidential Data Plan.	Free Free and open source.
Web	macOS, Web, Browser extension, Command line
Tuned for academic and technical writing Includes plagiarism, AI detection and citation tools	All checks run locally with no telemetry Works in browsers, editors and system-wide on macOS
Less suited to casual or marketing writing Strongest privacy guarantees are on a paid plan	English only Rule-based checks do not rewrite text the way AI assistants do
Web application	Downloadable app, Web application, Browser extension
Closed source	Open source
License not stated	License not stated
Not stated if an account is needed	Not stated if an account is needed
Needs internet	Works offline
Official website Full listing and sources Checked September 26, 2026	Official website Full listing and sources Checked September 26, 2026

Catalog facts only. Anything “not stated” is unconfirmed. Check full listings for details.