QuillBot, featured on Quasa.io, is an AI writing and paraphrasing tool that helps students, writers, professionals, and content creators rephrase text, improve clarity, fix grammar, summarize content, and generate ideas while maintaining original meaning. Key features include a Paraphraser with multiple writing modes (Standard, Fluency, Creative, Formal, etc.), a Grammar Checker, a Summarizer for condensing long articles, and AI Content Tools such as a plagiarism checker, citation generator, translator, and AI essay/outlines writer. It offers generous word and character limits even on free plans, with premium unlocking unlimited usage, and integrates with Microsoft Word, Google Docs, Chrome extension, and mobile apps. In 2026, QuillBot remains a go-to tool for writing assistance. Downsides include daily limits on the free version for premium modes and word count, and that very long documents require premium. It has a rating of 4.8/5 stars.