JustDone AI vs Undetectable AI: Different Jobs
These two tools show up in the same searches, but they are not the same kind of product. JustDone AI is a writing suite that includes a humanizer among templates, generation, and other writing tools. Undetectable AI is a humanizer: it rewrites an AI-assisted draft. Comparing them only makes sense if you say which job you are hiring.
If the job is “make my own draft read more like me,” a dedicated humanizer is the closer match. If you want a bundle of writing tools, JustDone's suite is the product on offer — at a higher monthly price after the trial. Our SupWriter vs NaturalWrite page compares SupWriter with NaturalWrite. SupWriter is not affiliated with NaturalWrite.
Price, Trial, and What You Can Verify
Checked 2026-09-26, JustDone's public terms are a $2 trial that lasts 7 days. It renews at $29.99/month unless you cancel at least 24 hours before the trial ends. Trustpilot shows 4.3/5 from about 9,400 reviews. Undetectable AI is listed from $9.99/month with a limited free-word allowance.
- JustDone AI: writing suite, $2 for 7 days, then $29.99/month. Cancel at least 24 hours before the trial ends if you do not want the renewal.
- Undetectable AI: humanizer, from $9.99/month, limited free words. Confirm the current word cap on their pricing page before you subscribe.
- SupWriter: humanizer from $9.99/month. Basic is 5,000 words a month and 500 words per request. Free is 300 words total, with a free account and no card. The editor covers 50+ languages.
SupWriter also includes an AI detector: one score and sentence highlights. Use it as a pre-check on your draft. It is one scoring model, not the detector your school or client uses. Results vary, and no tool can guarantee a result.
JustDone's Trial, in Plain Terms
The $2 charge is the trial, not the subscription. The trial runs 7 days. If it is still active 24 hours before it ends, the plan renews at $29.99/month. That renewal is in the terms. Put the end date on a calendar when you sign up.
Trustpilot's public rating for JustDone is 4.3/5 from about 9,400 reviews. Ratings move, so check the current page if the number matters to you. The price and the 24-hour cancellation window are the terms to read either way.
Undetectable AI's listed starting price is $9.99/month, the same shelf as SupWriter Basic. SupWriter's free tier is 300 words, a free account, and no card. Paid plans are monthly word caps, not an open-ended allowance: 5,000, 15,000, or 30,000 words a month depending on Basic, Pro, or Ultra.
Undetectable AI: The Dedicated Humanizer of the Two
Between JustDone and Undetectable AI, the humanizer is Undetectable AI if that is the only feature you need. You are not paying $29.99 for a suite. You are paying a humanizer price that starts at $9.99/month. Word caps and higher tiers are on their pricing page — use those, not a performance percentage.
A humanizer rewrites wording. It does not decide what a school or a client will conclude about a draft. If you want to see how Undetectable AI sits next to other humanizers on price and features, our AI humanizer overview covers the category without treating any score as a promise.
Where SupWriter Fits
SupWriter is for a draft you are already responsible for. It rewrites AI-assisted text so it reads more naturally in your own voice, in 50+ languages. You can then run the built-in detector: one score, with sentence highlights, before you submit. That check is not Turnitin, GPTZero, or any other named product. SupWriter does not publish a pass rate, because no tool can guarantee what another detector will say.
On price, Basic is $9.99/month or $4.99/month billed annually, with 5,000 words a month and 500 words per request. Pro is $19.99/month or $9.99/month annually (15,000 words, 2,000 per request). Ultra is $39.99/month or $19.99/month annually (30,000 words, 5,000 per request). The humanizer, paraphraser, and grammar checker require a login.
For a plain explanation of how detectors score a draft, our AI Detection Hub covers how the tools work. It is background reading, not a promise about any rewrite.
Related Resources
- SupWriter vs NaturalWrite — A NaturalWrite alternative. SupWriter is not affiliated with NaturalWrite.
- Undetectable AI Alternatives — Other humanizer options
- Best AI Humanizer Tools (2026) — Category overview
- AI Detection Hub — how detectors work
- Does Turnitin Detect AI? — What the detector reports