Runs inside Google Docs
Operates on the open document.
Write It
Gemini in DocsBuilt in
Grammarly
QuillBotExtension
Wordtune
ProWritingAid
Roundup
6 best AI writing assistants for Google Docs
Six assistants that genuinely operate in Google Docs, ranked by how much of the writing they help with rather than how loudly they market themselves.
Write It teamUpdated 6 min read
Plenty of tools claim to work with Google Docs. Fewer actually operate on the document — many just mean "we have a Chrome extension that notices you are typing." This list separates them, and ranks by how much of the writing each one genuinely helps with.
Extensions vs add-ons, briefly
Worth understanding before installing anything. A Google Workspace add-on runs in a sandboxed sidebar with access mediated by Google’s APIs. A Chrome extension runs in the browser alongside the page and can do more — including simulating real typing into the document, which an add-on cannot.
That extra capability comes with broader permissions. An extension that types into your documents can read them, so it is worth knowing who built it.
The 6 assistants at a glance
| Feature | Write It | Gemini in Docs | Grammarly | QuillBot | Wordtune | ProWritingAid |
|---|---|---|---|---|---|---|
| Runs inside Google DocsOperates on the open document. | Built in | Extension | ||||
| Generates original draftsWrites new prose from a brief. | ||||||
| Multi-step agent that plans then draftsOutline, draft, revise as separate phases. | ||||||
| Types keystroke by keystrokeText arrives as typing, not insertion. | ||||||
| Grammar and style checkingLive underlines while you write. | ||||||
| Rewrites and paraphrasesRephrases a passage you select. | ||||||
| AI humanizer and detectorRewrites machine-sounding prose and scores your draft. | Detection only | |||||
| Source discovery and Works CitedFinds sources and builds a bibliography. | Generator only | |||||
| Free tierUsable without paying. | On eligible plans |
Generates original drafts
Writes new prose from a brief.
Write It
Gemini in Docs
Grammarly
QuillBot
Wordtune
ProWritingAid
Multi-step agent that plans then drafts
Outline, draft, revise as separate phases.
Write It
Gemini in Docs
Grammarly
QuillBot
Wordtune
ProWritingAid
Types keystroke by keystroke
Text arrives as typing, not insertion.
Write It
Gemini in Docs
Grammarly
QuillBot
Wordtune
ProWritingAid
Grammar and style checking
Live underlines while you write.
Write It
Gemini in Docs
Grammarly
QuillBot
Wordtune
ProWritingAid
Rewrites and paraphrases
Rephrases a passage you select.
Write It
Gemini in Docs
Grammarly
QuillBot
Wordtune
ProWritingAid
AI humanizer and detector
Rewrites machine-sounding prose and scores your draft.
Write It
Gemini in Docs
GrammarlyDetection only
QuillBot
Wordtune
ProWritingAid
Source discovery and Works Cited
Finds sources and builds a bibliography.
Write It
Gemini in Docs
Grammarly
QuillBotGenerator only
Wordtune
ProWritingAid
Free tier
Usable without paying.
Write It
Gemini in DocsOn eligible plans
Grammarly
QuillBot
Wordtune
ProWritingAid
Checked August 2026. Google in particular changes which plans include which AI features fairly often — check your own account.
1. Write It
Write It is a Chrome extension built specifically around Google Docs, and it covers more of the writing process than anything else on this list. It reads the open document, works on it in place, and puts text in the way typing does rather than as an insertion.
The toolkit runs from one sidebar: Apollo Agent Mode for multi-step drafting with a review step before anything lands, an auto typer with variable speed and self-corrected typos, a humanizer, an AI detector that scores your own draft, Research Mode for sources and citations, a Writing Assistant for live grammar and clarity underlines, and inline tab completion that suggests the next phrase as you type.
It also runs in Microsoft Word on the web and, with a lighter feature set, Google Slides.
Key features of Write It
- Auto Typer. Variable WPM, natural mistakes with corrections, and sentence-end pauses. Write It Max adds pacing that reacts to sentence complexity.
- Apollo Agent Mode. Plans, drafts, and revises inside the doc, showing you the draft before it is written in.
- Tab completion. Inline ghost-text next-phrase suggestions.
- Writing Assistant. Spelling, grammar, punctuation, clarity, conciseness, tone, repetition, word choice, passive voice.
- AI Humanizer and Detector. Rewrite machine-sounding phrasing, and see what still reads that way.
- Research Mode. MLA 9, APA 7, Chicago, or IEEE, source discovery, and a Works Cited inserted into the doc.
- Highlight Mode. Select a passage and get a direct AI edit on that selection.
Pros and cons of Write It
Pros
- Widest feature coverage of any assistant that runs in Google Docs
- The only one that types rather than inserts, which matters for version history
- Research and citations included, not a separate subscription
- Free tier with no card required
- Also works in Microsoft Word on the web
Cons
- Grammar checking is not as deep as Grammarly’s or ProWritingAid’s
- Browser only — no desktop or mobile app
- Requires broad extension permissions to read and type into documents
- AI features are token-metered
See it in your own document
Install free and run one paragraph through the typer and the humanizer.
2. Gemini in Google Docs
Google’s Help me write is already in the sidebar with nothing to install, on eligible plans. For a nudge past a blank page or a quick rewrite of an awkward sentence, that convenience is real and worth using before you pay for anything else.
It generates and refines text and stops there. No humanizer, no detector, no source management, and it inserts text instantly rather than typing it.
Pros and cons of Gemini in Docs
Pros
- Nothing to install and no extra subscription on eligible plans
- First-party, so it will not break when Docs changes
Cons
- Inserts text instantly — a visible single edit in version history
- No humanizer, detector, source library, or bibliography
- Many school Google accounts do not include it
- Availability and plan tiers change frequently
3. Grammarly
Grammarly works in Google Docs through its Chrome extension and remains the strongest proofreader available. It catches more than the alternatives, explains its suggestions, and handles tone and formality with real nuance. It is also the only tool here that follows you into desktop apps and mobile.
Pros and cons of Grammarly
Pros
- Best grammar and style engine in this group
- Works outside the browser, which nothing else here does
Cons
- Reacts to existing text — limited help producing it
- No source discovery or bibliography building
- Clarity and tone suggestions are behind the paid tier
- Two sets of underlines can get visually noisy alongside another assistant
4. QuillBot
The most controllable rewriter here, with real granularity over how far a rewrite departs from the original. Its Chrome extension reaches into Docs, though the web app remains its main surface, which means a round trip for anything substantial.
Pros and cons of QuillBot
Pros
- Best rewrite control of anything on this list
- Bundles a summarizer, citation generator, and plagiarism check
Cons
- Web app is the primary surface — formatting suffers on the round trip
- Rewrites text you supply; no help with a blank page
- Per-rewrite word limits on the free tier
- No source discovery
5. Wordtune
Focused on the sentence. Select a clunky line and get several rewrites with control over tone and length. For tightening individual sentences it is fast and good; for restructuring a section it is the wrong tool.
Pros and cons of Wordtune
Pros
- Excellent at sentence-level rephrasing
- Tone and length controls are genuinely useful
Cons
- Sentence-scoped — little help with structure or argument
- No research, citation, or detection features
- Free tier caps rewrites per day
- Narrower than most alternatives here
6. ProWritingAid
The most detailed style analysis in this group — twenty-plus reports covering readability, sentence variety, pacing, overused words, sticky sentences, and more. It is built for long-form writers, and for a student it can be more information than is actionable.
Pros and cons of ProWritingAid
Pros
- Deepest style reporting of anything here
- Sentence variety and readability reports genuinely improve prose
Cons
- Report volume is overwhelming for a short essay
- Slower than the lighter checkers
- Docs integration is less seamless than Grammarly’s
- No generation, research, or detection features
What most students should install
- Start with what is free. Try Gemini if your Google plan includes it. Costs nothing and may be enough for light help.
- Add one that covers the whole job. If your work is essays and research papers in Docs, Write It covers drafting, typing, research, and citations in one place.
- Add a proofreader only if mechanics are your weak point. Grammarly if your feedback is about commas. If it is about argument and structure, spend the money elsewhere.
- Do not run four at once. Overlapping underlines make Docs unusable and the browser slow.
The one that does the most inside your doc
Install Write It free — drafting, typing, humanizing, research, and citations in Google Docs.
Frequently asked questions
What is the best AI writing assistant for Google Docs?
Write It for breadth — it is the only one that covers drafting, keystroke-level typing, humanizing, detection, research, and citations inside the document. For proofreading specifically, Grammarly is stronger.
Does Google Docs have a built-in AI writing assistant?
Yes, on eligible Google plans — Help me write generates and refines text in the sidebar. Availability is tied to specific plan tiers and many school-issued accounts do not include it.
Can I use more than one at the same time?
Technically yes, and two is usually the practical limit. Multiple assistants underlining the same sentence gets visually noisy fast and slows the browser down.
How much does Write It cost?
Write It is free to start with 5,000 tokens at signup. Plus is $10 a month or $96 a year and includes 100,000 tokens a month. Premium is $15 a month or $144 a year and includes 200,000 tokens a month. Unused tokens roll over on both paid plans.
Does Write It work outside Google Docs?
Write It runs in Google Docs with the full toolkit, in Microsoft Word on the web, and in Google Slides with a lighter feature set.