Undetectable.ai is one of the best-known names in its category, and that category is the bypass humanizer: tools built to rewrite AI text so it reads past common detectors. A detector view was added later, mainly to check the humanizer's own output. TextSight sits on the other side of that line. Detection is the whole product, every scan comes back with sentence-level evidence, and the bundled rewriter is there to help you fix what flags honestly, so the writing reads as your own. To be clear about our own bias up front: TextSight is a detection tool and does not help anyone evade detection. This page lays out what each product is actually for, where Undetectable's reputation is earned, and why the two are answering opposite questions.
A short table first, framed around the difference that actually matters: one product is built to detect AI honestly, the other is built to read past detectors. The narrative below goes deeper.
| What you are comparing | TextSight | Undetectable.ai |
|---|---|---|
| What it is built to do | Detect AI honestly and help you fix it | Rewrite AI text to read past detectors (bypass humanizer) |
| The detector's job | Score arbitrary writing, with a readable methodology | Check the humanizer's own output, not arbitrary writing |
| Sentence-level evidence | Yes, colour-coded per sentence with a reason per line | No, the UI does not surface per-sentence detector signals |
| What the rewriter is for | Honest pre-publish cleanup that keeps facts and citations | Aggressive rewriting aimed at lowering a detector score |
| Stance on evading detection | Does not help evade detection, by design | Bypass is the product's stated purpose |
| ESL false-flag calibration | Core focus, since detection is the whole product | Not the focus; the bundled detector checks rewrites |
| Free tier, first scan | 3 scans/day, 5,000 chars, no signup for the first scan | Limited free preview gated behind signup |
| Brand recognition in its lane | Younger, competes on the detection side | One of the best-known names in bypass humanizers |
| Who it fits | Teachers, editors, agencies, writers who want honest results | People whose stated goal is reading past detectors |
Undetectable.ai is, by its own positioning, a bypass humanizer; its bundled detector checks its own rewrites rather than scoring arbitrary writing, which is why this page frames the two as answering opposite questions. TextSight is a detection tool and does not help evade detection. "Win" markers reflect our reading of each tool's purpose, not a third-party audit.
An honest comparison should name a competitor's real strengths. Here are three, stated plainly, even where they are not the job TextSight is built for.
Undetectable.ai has put its effort into one surface, the rewrite engine, and that focus shows. The aggression controls, the workflow, and the browser extension are smooth in the way a single-minded product team tends to deliver. TextSight ships a rewriter too, but as one part of a detect-and-fix workflow rather than the centre of the product. On the rewrite surface specifically, Undetectable has built more depth.
"Undetectable.ai" is among the most recognised brand names in the bypass-humanizer space. Name recognition is real, and for people already searching that category it is the name they reach for first. TextSight is younger and competes on the detection side, so it earns attention on substance rather than recall. If brand familiarity in that lane matters to you, Undetectable has it.
Whatever one thinks of the category, Undetectable does the thing it says on the tin. If your explicit goal is to make AI text read past common detectors, it is a serious tool for that purpose, and we are not going to pretend otherwise. That is simply a different goal from the one TextSight serves, which is why most of this page is about why the two are not interchangeable.
If reading past detectors is genuinely your aim, Undetectable is the category to look at, and the rest of this page is for context rather than persuasion. Just know that TextSight is built for the opposite outcome, covered next.
For teachers, editors, agencies vetting drafts, and writers who want their own work to read clearly as their own, here is what detection-first actually buys you.
Undetectable's bundled detector exists to check its own humanizer's output, so it tends to clear content that the two were tuned together to clear. That is not a neutral read on arbitrary writing. TextSight's detector is the centre of the product, tuned to score writing of any origin honestly, with a methodology you can read. A teacher grading an essay, an editor vetting a contributor, or a writer checking their own draft needs an independent detector, not a tool grading its own homework.
Every TextSight scan comes back as a per-sentence map with a short reason on each flagged line: the rhythm is flat here, the cadence too even there. You revise the exact sentences that read as machine-written and keep the rest. A bypass tool gives you a rewritten block and a low score; it does not show you what was wrong or let you decide what to change. When the goal is honest revision rather than wholesale replacement, that visibility is the point.
Carefully taught, non-native English often reads as "too clean," which is how honest students get wrongly flagged. Cutting that down is core calibration work for a detector, and TextSight treats it as central. A bypass tool's bundled detector is not built for that problem, because its job is to check rewrites, not to be fair to arbitrary student writing. For a classroom or institution scanning international students, a detector tuned for fairness is the right tool.
Undetectable's free path is a small preview behind a signup, with real use needing a paid plan. TextSight's free tier is 3 scans a day at 5,000 characters per scan, permanent, no card, and no signup for the first scan. For a teacher spot-checking a few essays, a writer between drafts, or anyone evaluating the tool, that permanence is what makes it usable day to day rather than just for a trial.
The bypass-humanizer framing reads fine inside some writing communities, but it is hard to take to a dean, a compliance lead, or a procurement committee. TextSight is a detection and honest-revision tool, which is straightforward to stand behind in an academic, editorial, or enterprise setting. We are not claiming the moral high ground over how any individual uses a tool; we are saying that what TextSight is built to do is easier to justify in the rooms where these decisions get made.
We could write this section as a chest-thumping "our detector catches their rewriter" table. We are not going to, because the more useful thing to explain is why chasing a low detector score is a shaky goal in the first place.
A bypass humanizer optimises for one thing: a low number on a target detector. The trouble is that there is no single detector. Detectors change, they disagree with each other, and institutions increasingly run more than one. So a score that looks clean on the tool you tested against can flag on the next one in line. Reading past one checker is not the same as your writing actually reading as your own, and the gap between those two is where the risk lives.
TextSight is built around the opposite move. Instead of disguising AI text, you scan a draft, see exactly which sentences read as machine-written, and revise those parts so the writing is genuinely yours. When prose reads as human because it was actually revised by a human, it does not depend on beating any particular detector. That is a more durable outcome than a number that holds only against the one tool you happened to check.
To be direct about it: TextSight will not help you slip AI work past a teacher, an editor, or a client. That is not a limitation we are apologising for; it is the point of the product. If your goal is to pass off AI-generated text as your own, we are not the tool, and we would gently push back on the goal itself given how the landscape is moving. If your goal is to write honestly and confirm it reads that way, that is exactly what TextSight is for.
So there is no fair head-to-head score to print here, because the two products are not trying to win the same game. Undetectable is built to lower a number. TextSight is built to tell you the truth about a draft and help you fix it for real. Pick based on which of those outcomes you actually want, not on a benchmark that would only flatter whoever wrote it.
Once you see the shape of each product, every other difference follows from it. Worth understanding before the pricing makes the two look more comparable than they are.
Undetectable is built around the rewrite engine. The humanizer is the main surface, the aggression control is the main dial, and the bundled detector is there to confirm the rewrite came out below the company's own threshold. That makes it effective at its stated job. It also means the detector is not built to read arbitrary writing fairly, and the bypass framing in the name and marketing is awkward to carry into a classroom, a newsroom, or a procurement review.
TextSight is built the other way. The detector is the centre, with per-sentence evidence, a reason on each flagged line, and a methodology you can read. The rewriter is bundled for one purpose: after a scan shows which rhythms read as AI, you revise those specific sentences while keeping your meaning, then recheck. The framing is honest revision, not score reduction, which is straightforward to defend wherever these decisions actually get made.
Hand each tool a paragraph and watch what it hands back. Undetectable returns a rewritten paragraph and a low score on its own checker, often reading as though a different writer redid it from scratch. TextSight returns a per-sentence map showing which lines still read as machine-written, so you can fix those yourself and keep your vocabulary, your structure, and your citations. One outcome is a number. The other is a draft you understand and can stand behind.
TextSight Pro is $19.99 monthly, or $14.99 monthly on annual billing, with unlimited scans plus the bundled rewriter. Undetectable.ai prices a bypass-humanizer workflow, at the rates on its own site. The two are not the same purchase, so the sticker is the wrong place to compare them.
Billed $89.88/year, Save $30
Billed $179.88/year, Save $60
Billed $359.88/year, Save $120
Yearly billing saves 25%. Undetectable.ai prices its bypass-humanizer plans on its own site; we do not restate them here because they change and they buy a different kind of product. View full pricing →
These tools answer opposite questions, so the choice is really about which question is yours. Use this picker to be honest with yourself about that.
If those two lists describe two different people, that is the point. TextSight is built for the second one, and does not try to be the first.
These are the jobs TextSight is built for: knowing whether writing reads as AI, and fixing what does without faking it. Three concrete profiles.
Most of the pile is honest student work, some of it written in carefully taught, non-native English, and a few essays raise a quiet flag. This is squarely TextSight's job. The detector is tuned to be fair to formally-taught English, so honest students are less likely to be wrongly accused, and the per-sentence evidence lets the teacher see whether a flagged passage is the student's real voice or genuinely templated before saying anything. A bypass tool is the wrong shape here entirely; it is built for the people being graded, not the person grading.
Contributors send work that may or may not have started with AI, and it goes out under the publication's name. The editor needs an honest read, then a way to fix what reads as machine-written without flattening the writer's voice. TextSight does both: detection on every submission, sentence-level evidence to guide the edit, and the bundled rewriter to clean up the flagged rhythms while keeping facts and citations intact. The goal is a draft that genuinely reads as human writing, not one disguised to pass a checker.
Used AI to brainstorm or outline, then wrote the piece themselves, and wants to be sure the final draft reads clearly as their voice. TextSight is the right tool. Scan it, see if any passages still carry an AI rhythm, revise those honestly with the rewriter's help, and recheck. The outcome is writing that reads as human because it was actually shaped by one, which holds up no matter who checks it later. That is a different aim from making AI text slip past a detector, and it is the one TextSight serves.
The full detector ranking on accuracy, evidence, pricing and use-case fit, side by side.
See the ranking →Another detector head-to-head, on accuracy, evidence, and how each one reads a draft.
Read the compare →What a detector actually measures, why edited AI is harder to catch, and how to read a score.
Read the explainer →The detection-first alternative for people who want to find and honestly fix AI writing.
See the alternative →Start with TextSight's free tier. No card, no signup, no commitment. Your first scan in about six seconds.
Honest head-to-heads with other detectors and humanizers.