Related
- HumanFlow vs Undetectable.ai — where we sit against the first of these, including where it beats us.
- HumanFlow vs Walter Writes — and against the second.
- Every humanizer we track, ranked — on published limits rather than on claims.
Undetectable.ai vs Walter Writes
HumanFlow is not one of the two tools on this page. We make a competing product, so weigh this accordingly — our methodology sets out how we source competitor figures and what we refuse to claim.
How you pay decides this one. Monthly, Walter Writes is cheaper and gives three times as much; yearly, it becomes the dearer of the two without changing its price.
Last reviewed 16 August 2026 · The HumanFlow team
Why people compare these two
Both are sold as products rather than single-purpose rewriters — each has a browser extension and a public API — and their entry prices sit two dollars apart. They are the two names that come up when someone wants humanizing available somewhere other than a web form.
Which one is cheaper has two different correct answers, and neither pricing page makes that visible, because working it out means noticing something one of them does not print.
Side by side
| Feature | Undetectable.ai | Walter Writes |
|---|---|---|
| Entry price, monthly | $9.99 | $8 |
| Entry price, billed yearly | $5 | Not published |
| Included at entry | 10,000 words / month | 30,000 words / month |
| Per-request cap | No stated per-request cap | Not stated in the material we could retrieve |
| Free tier | 250-word trial | 300-word trial, no card or login |
| Free per request | 250 words | 300 words |
Undetectable.ai figures read from their pricing page on 15 August 2026; Walter Writes from theirs on 4 August 2026.
What actually separates them
Month to month it is not close. Walter Writes is $8 for 30,000 words against Undetectable.ai's $9.99 for 10,000 — three times the allowance for two dollars less.
Billed annually it inverts. Undetectable.ai falls to $5 a month, $60 for the year, the lowest annual entry we track alongside Twixify. Walter Writes publishes no annual rate at all, so it stays at $8 a month and $96 a year. The cheaper plan becomes the dearer one purely because one company offers a discount for committing and the other does not.
Neither tells you what a long document needs. Undetectable.ai states no per-request cap on its pricing page; Walter Writes states none in anything we could retrieve. Both monthly allowances are therefore theoretical for anyone pasting a chapter, and on the single axis where these two could have separated themselves they are equally silent.
Where Walter Writes is plainly broader is reach: shipped iOS and Android apps, a free MCP connector, published developer documentation, and an API priced openly across six tiers from $49 to $1,699 a month. Undetectable.ai answers with a Chrome extension, its own public API, and image and PDF checking that Walter Writes does not advertise. Their free tiers are near enough identical to ignore — 300 words against 250, one-time on both, neither enough to judge a real document on.
Which to pick
Pick Undetectable.ai if you will commit for a year, where $60 is the lowest annual entry in the set and matched only by Twixify, or you need image and PDF checking alongside text.
Pick Walter Writes if you pay monthly, you want the larger allowance, or you want the humanizer where you already work — extension, phone, MCP or your own code. Buying month to month, that combination settles it.
The claim we won't compare on
Neither tool's ability to get text past an AI detector appears above, and it is not an oversight. No vendor can observe or control the systems such a claim is about, detectors change without notice and disagree with each other on identical text, and every published bypass rate in this category was produced by the company selling the tool it tested. We publish none for our own product either — see why we publish no bypass rates.