QuillBot

The platform bundles a paraphraser, grammar checker, AI detector, plagiarism checker, humanizer, summarizer, translator, citation generator, image generator, and PDF tools under one login, with a Chrome and Edge extension that follows you outside the platform. The free tier is real and permanent — no expiry, no card required — but the features that matter most for professional use, specifically advanced writing recommendations and full plagiarism checking, are paid-only. The paraphrasing and grammar tools are where QuillBot built its reputation; the image generation and presentation tools are newer additions that the vendor positions as a full creative suite but that community reports suggest are thinner than the writing core. No API is available, so you cannot embed any of this into your own product pipeline — every workflow runs through their UI or extensions.