Grammarly vs QuillBot vs Wordtune: AI Writing Assistant Compared

Grammarly's parent company renamed itself "Superhuman" in October 2025, uniting Grammarly, Coda, and Superhuman Mail under one corporate brand with a new cross-app AI assistant called Superhuman Go. The consumer writing product itself is still called Grammarly — only the parent company changed names.

Grammarly remains the most ubiquitous — it works inside almost every app you type in, and is expanding into a broader productivity suite under its new Superhuman parent brand. QuillBot leans hardest into paraphrasing specifically, bundled with citation and AI-detection tools aimed at students. Wordtune is the simplest and cheapest of the three, focused narrowly on rewriting and tone rather than a full feature suite.

Grammarly's biggest advantage is simply reach — it checks your writing everywhere, not just inside one app. Its expansion into Coda (renamed Superhuman Docs) and Superhuman Mail means it's increasingly a bundled productivity ecosystem rather than a standalone grammar checker, which is worth knowing if you're evaluating it purely as a writing tool.

QuillBot's paraphrasing engine, with multiple distinct rewrite modes, is the strongest of the three specifically for rephrasing existing text — and its bundled citation generator and AI-detector/humanizer tools are aimed squarely at students and researchers dealing with both writing and AI-detection anxiety in the same workflow.

Wordtune is the cheapest of the three by a clear margin, and doesn't try to be a full suite — just a lightweight tone-and-rewrite tool. That makes it a good fit for casual users or non-native English writers who want help with individual sentences without paying for features they won't use.

Wordtune is the cheapest at around $4.89/month billed annually, QuillBot's Premium tier runs about $8.33/month annually, and Grammarly's Pro tier is $12/month annually — with Grammarly's bundled Business tier (including Superhuman Mail) running considerably higher for teams wanting the full suite.

For everyday, everywhere grammar and style checking — especially if a broader productivity suite appeals — Grammarly is the most complete option. For students specifically needing paraphrasing, citations, and AI-detection together, QuillBot is the more purpose-built choice. For a simple, cheap rewriting tool without extra features, Wordtune is the lightest option of the three.