AI tools for the whole essay cycle.
See what reads like AI in your draft, then humanize, rewrite, and proofread it — free in the browser, no signup wall.
The Student AI Workflow
Many students using ChatGPT run into the same problem: getting from first draft to something they can review, revise, and submit with more confidence.
Write with ChatGPT
You draft an essay, report, or assignment using ChatGPT, Gemini, or any AI assistant. The output is well-structured but reads like a machine wrote it.
Your Institution Checks It
Your university runs the submission through Turnitin, GPTZero, or whatever it has licensed. You do not get to see that result first, and neither do we — we have no way to test against those tools.
Check It Yourself First
Run the draft through Coda One's AI Detector. It shows you which sentences read like machine writing — formulaic transitions, stock openers, flat rhythm — so you know which paragraphs need your attention.
Fix What It Flagged
Humanize or rewrite the flagged passages, then run the Grammar Checker over the result. Re-check with the Detector — it is free with no daily limit, so there is no reason not to.
4 Tools, One Loop
From first draft to final submission: check what reads like AI, rewrite it, then proofread it. All free to start, no account required.
4 AI Tools in Your Right-Click Menu
Stop switching tabs. Install the Coda One Chrome extension and access your most-used tools from any webpage. Select text, right-click, and detect AI, humanize, rewrite, or check grammar without leaving the page.
- Detect AI — see which sentences read like machine writing
- Humanize — rewrite AI text to sound natural
- Rewrite — say the same thing another way
- Grammar Check — fix errors in any text field
Free to install. Works on any website. No account required.
You Can Use All of It Without a Card
Most AI writing tools want a payment method before they show you anything. Every tool here has a free tier that asks for nothing — no card, and for the detector, not even an account.
Free start, whole workflow
The Humanizer, Rewriter and Grammar Checker each give you 3 runs a day, and the counter resets at midnight UTC. That is enough to take one essay through the whole loop before you decide whether it is worth paying for.
No account for the detector
The AI Detector takes no signup, has no daily limit, and publishes its measured error rates — including the cases it gets wrong. If you only ever use one thing here, that is the one that costs you nothing and hides nothing.
Works on Slow Connections
The AI Detector answers in under a second with no daily limit. Writing tools show results as they generate, and the free tier needs no signup — paste, run, done.
How Coda One Compares
Most students juggle 3-4 different tools. Coda One replaces them all with one free platform. Here is how we stack up against alternatives you have probably tried.
| Feature | Coda One | QuillBot | Grammarly | Undetectable AI |
|---|---|---|---|---|
| AI Humanizer | Yes (free tier) | No | No | Yes ($9.99/mo) |
| AI Detector | Yes (web app) | No | Premium only | Yes (limited) |
| Grammar Checker | Yes (free tier) | Yes (limited) | Yes (limited) | No |
| Rewriter | Yes (8 modes) | Yes (limited) | Premium only | No |
| Chrome Extension | Yes (free) | Yes | Yes | No |
| Free Tier | Unlimited detector + 3/day each | 125 words | Unlimited basic grammar | 250-word trial, then paid |
Competitor figures checked against each vendor's own pricing page on 28 August 2026. They change these often; if you are deciding on the strength of a row, check theirs too.
Frequently Asked Questions
Is Coda One really free?
The AI Detector is free with no daily limit and no account — up to 3,000 words a check. The AI Humanizer, AI Rewriter and Grammar Checker give you 3 free runs a day each. Paid plans start at $9.99/month and are only worth it once you hit those limits.
Do I need to create an account?
You can start most tools in your browser before creating an account. Create one only if you want to save history or upgrade to a paid plan.
Does the AI Humanizer bypass Turnitin?
We do not claim that, and we have not measured it. We have never run our output against Turnitin, GPTZero or Originality.ai, so anyone telling you a pass rate — including us — would be guessing. What the tool does do is rewrite phrasing that reads as machine-written. Our own detector's measured error rates are published at /ai-detector/accuracy.
Is it safe for academic use?
Our tools help you improve your writing. Use them responsibly per your institution's AI policy. The humanizer preserves your arguments while making text sound more natural.
Is there a Chrome extension?
Yes. Install the free Chrome extension for right-click access to Detect AI, Humanize, Rewrite and Grammar Check on any website — every tool we run, without leaving the page.
What's the word limit for free users?
The detector takes 3,000 words a check. The Humanizer and Rewriter take 300 words a run and the Grammar Checker 500 — 3 runs a day each. Paid plans raise the per-run limit and drop the daily cap.
Does it work on mobile?
Yes. All web tools work in mobile browsers. The Chrome extension works on desktop Chrome.
Is my data private?
Text is processed for your request and never used to train models. Signed out, nothing is kept in an account. Signed in, the Humanizer, Rewriter and Grammar Checker save the input and result to your own tool history, which you can delete; the Detector never does. /privacy names exactly which third party each tool sends text to.
How does Coda One compare to QuillBot or Grammarly?
Coda One gives you an AI detector with no daily limit, an AI humanizer, and a rewriter in one connected flow — check a draft, then fix it in one click. QuillBot focuses on paraphrasing and Grammarly on grammar; Coda One covers the loop from detection to final polish.
Start Writing Better — Free
Start with the student workflow in your browser. Move to a paid plan only if you need more daily writing capacity.