Undetectable.AI is the most recognized brand in the AI rewriter category and a clear leader in the student score-reduction market. The product is built around rewriting AI text to lower scores on common detectors, and a small bundled detector validates the AI rewriter's own output. TextSight comes at the same problem from a different direction, built for the student who wrote the essay themselves and wants an honest pre-submission read. The detector is the centre of the product with sentence-level highlights and a published methodology, and the AI rewriter is bundled for the calibration workflow rather than the score-reduction loop. This page is the honest student comparison: where Undetectable is the right call for some workflows, where TextSight is the better fit for an ethical student workflow, and why permanent score reduction is not a strategy worth betting your degree on.
A short feature table first, framed around what an actual student workflow needs the night before a deadline. The narrative sections below go deeper, including the parts where Undetectable is genuinely the better call for some users.
| Feature for a student workflow | TextSight | Undetectable.ai |
|---|---|---|
| Primary product | Calibration detector with sentence-level evidence, ethical AI rewriter bundled | Score-reduction AI rewriter with a validation-only detector view |
| Detection type | Independent classifier, scores arbitrary writing | Not a real detector, validates the AI rewriter's own output |
| Free tier | 3 scans/day at 1,500 words, permanent, no signup for first scan | One-time AI rewriter preview gated behind email signup, around 250 words |
| Pricing model | Flat monthly subscription with detection plus AI rewriter bundled | Credit packs $5 to $200/mo, AI rewriter-only allowance |
| Entry price | $9.99/mo Starter, detection included | $9.99/mo entry pack, AI rewriter credits only |
| Pro annual effective | $14.99/mo billed yearly ($179.88/year) | No equivalent Pro tier published, credit packs scale linearly |
| .edu discount | $13.99/mo verified .edu Pro, billed monthly, no lock-in | No student or .edu pricing tier published |
| Sentence-level evidence | Per-sentence colour map with rationale, on every tier including free | Single confidence score, no per-line evidence on output |
| ESL FPR | 6% on internal 100-passage ESL benchmark | Not published, detector not tuned for ESL accuracy |
| Native FPR | 3% on internal 100-passage native English benchmark | Not published, detector role is validation only |
| GPT-4 TPR | 92% on internal 100-passage GPT-4 benchmark | Not applicable, product is an AI rewriter not a detector |
| Claude TPR | 90% on internal 100-passage Claude benchmark | Not applicable, product is an AI rewriter not a detector |
| Bundled AI rewriter | Rhythm-aware single-pass AI rewriter, 20,000 words/mo Starter, 50,000/mo Pro | Multi-pass Light, Balanced, Maximum modes, credit-metered |
| REST API | Yes, on Business tier at $29.99/mo yearly | Yes, separate API pricing, AI rewriter-only endpoints |
| Best fit | Students pre-scanning their own essays before submission | Users committed to score-reduction-first rewriting regardless of integrity framing |
Pricing verified May 2026. Verify on each tool's pricing page before subscribing. "Win" markers reflect our reading of the feature gap from a student perspective.
Four areas where Undetectable does a job TextSight does not try to do. Acknowledging them is the point of writing this page in the first place, even though our framing is that the score-reduction workflow is not the right student strategy long term.
Undetectable.ai has been shipping an AI rewriter-centred workflow since 2023, and the focus shows. The rewrite engine, the multi-pass aggression slider, and the Chrome extension are polished in the way that only a singularly-focused product team delivers. TextSight ships a competitive AI rewriter inside a broader detect-plus-rewrite workflow, but the depth Undetectable has built on the rewrite surface specifically is genuinely deeper.
This is the core reason most users pick Undetectable, and it is not marketing. On Maximum mode the AI rewriter runs multiple rewrite passes and is willing to break voice and cadence to drive scores toward zero on a basket of common detectors. For a student whose only metric is the AI percentage on a specific detector, the multi-pass approach delivers numerically. TextSight's single-pass rhythm rewrite trades a few points of score reduction for output that still reads like the source writer, which is the wrong trade-off if pure score chasing is the goal.
Undetectable.AI is one of the most searched AI rewriter brand names in student rewriter forums and informal study groups. If a peer recommends a tool by name, brand recognition shortens the path to first use. TextSight is younger and competes on substance and bundle math rather than name recall, so for a student who only knows the rewriter keyword, Undetectable is the search result they hit first.
Undetectable's annual billing is the most aggressive in the category, with effective monthly rates dropping by roughly half on a year commitment. For a graduate student running a dissertation through an AI scaffold and willing to prepay a year, the per-word AI rewriter cost is competitive. The commitment risk is real, but for predictable high-volume rewriting the annual plan wins on raw cost.
If you fit any of those patterns, the rest of this page is informational rather than persuasive. Undetectable is the tool that workflow asks for. The TextSight position is that the workflow itself is a poor student strategy, but that is a separate argument from whether Undetectable delivers what it advertises.
For undergraduates pre-scanning their own English drafts, ESL students worried about over-flagging, and thesis writers iterating on long documents, here is where TextSight is the better student tool.
If you wrote the essay yourself and want an honest read on whether it will be misread as AI, you need a detector that scores arbitrary writing, not one tuned to clear its own AI rewriter's output. Undetectable's bundled detector exists to confirm rewrites land under an internal threshold. TextSight's detector is the centre of the product with a published methodology, scored sentence by sentence, the same way an independent classifier would read your draft. For a student calibration workflow, an independent detector is the only thing that gives you useful information.
Every TextSight scan returns a sentence-by-sentence colour map with a short rationale per line: rhythm flat, vocabulary cluster, paragraph cadence, sentence-length variance. You see exactly which six or seven sentences in a 1,500-word essay are pulling the score down, so you can rewrite those rhythms by hand or click the bundled AI rewriter on them. Undetectable returns a confidence score plus a wholesale rewrite, which is useful for score reduction but the wrong shape for editing an essay you mostly wrote yourself.
Detectors built on perplexity tend to over-flag formally-taught English from non-native writers because both the vocabulary and the sentence cadence have lower-than-average predictability. Undetectable's detector is not primarily tuned for ESL accuracy because the detector exists mainly to validate the AI rewriter's output. TextSight's rhythm scoring weights structural variance, which separates cleanly from vocabulary choice. Internal testing across Indian, Filipino, Nigerian and Chinese student writing shows roughly 40 percent lower false-positive rates than commodity perplexity-led detectors on identical-quality content.
Verified institutional emails such as .edu, .ac.uk, .ac.in, or .edu.au get TextSight Pro at $13.99 a month, billed monthly, with no annual lock-in. Pro includes unlimited scans, 10,000 character pastes, 90-day scan history, file upload, sentence-level highlights, and the bundled AI rewriter with 50,000 words a month. Undetectable.ai does not publish a student or .edu pricing tier today. For a graduate student or thesis writer, the .edu Pro tier is the most practical full-stack price point in the category.
If a marker asks how you prepared your draft, "I ran it through an AI detector to make sure my own writing was not being misread as AI" is a defensible answer. "I ran it through a score-reduction AI rewriter to lower my Turnitin reading" is a much harder conversation, regardless of whether the essay was originally yours. TextSight positions explicitly around calibration and pre-submission self-checking, which is the framing that holds up in an integrity review. Undetectable leans into score-reduction framing in its name and marketing, which creates awkward conversations in academic settings.
Because Undetectable.ai is an AI rewriter not a detector, the head-to-head is a catch-rate test rather than a TPR/FPR table. We ran 50 AI-generated passages through Undetectable at each of its three aggression modes (Light, Balanced, Maximum), then scored every output with the TextSight detector. The numbers below report how often TextSight still flagged the rewritten output as AI-shaped. Benchmark frozen 2026-06-03.
| Undetectable mode | TextSight still flags | Aggression notes |
|---|---|---|
| Light | 82% catch | Minimal vocabulary swap, voice preserved, easiest mode to catch |
| Balanced | 71% catch | Moderate sentence restructure, some voice drift |
| Maximum | 58% catch | Multi-pass aggressive rewrite, voice often broken, hardest mode to catch but introduces its own marker-visible signal |
If you wrote your essay yourself and used ChatGPT for a paragraph or two, the score-reduction workflow is the wrong shape for your actual risk. Your real worry is false-positive flagging on the honest 90 percent of your draft, not true-positive flagging on the AI-assisted 10 percent. A 6% ESL false-positive rate on TextSight versus 14 to 22 percent on competitor detectors is the metric that protects an honestly-written draft from being misread. Running the whole essay through Undetectable instead introduces the inconsistent-voice signal that markers and integrity panels learn to spot, even when no detector caught it.
The ESL false-positive trap is the single largest unfair-flag risk for international students. Perplexity-led detectors over-flag formally-taught English because both vocabulary and cadence have lower-than-average predictability. TextSight's rhythm scoring weights structural variance separately from vocabulary choice, which is why the ESL FPR drops to 6% on identical-quality content. The honest pre-scan workflow protects your draft. The score-reduction workflow rewrites a draft that did not need rewriting and shifts your voice into something a marker who knows you may question.
Undetectable's credit-pack model looks competitive at the smallest entry pack, but per dollar of useful work for a student writing one essay a week, TextSight's flat monthly subscription with detection bundled is meaningfully cheaper. The $13.99 .edu Pro tier gets you unlimited scans, 50,000 AI rewriter words, and 90-day history for less than half the cost of buying detection and authenticity separately. If your real workflow is pre-scan then targeted rewrite, the bundled price point wins at any realistic essay volume.
This is the part of the comparison most vs-pages skip. We think it is the most important thing for a student reader to hear, even when they came to this page looking for the strongest AI rewriter.
The detector vendors that institutions use are now backed by real research budgets and real model-iteration loops. What worked in May 2025 fails in October 2026 with embarrassing regularity. A score-chasing AI rewriter that posts a great score against current Turnitin can be a much worse bet six months later, by which time you may have submitted a transcript or thesis that gets re-checked.
The Maximum-mode rewrites that Undetectable is genuinely best at often introduce a different signal that markers and integrity panels notice: inconsistent voice. A paragraph in your usual register followed by a paragraph that suddenly reads like a thesaurus exploded is itself a flag, even if no detector caught it. The harder the rewrite, the more this happens.
If you actually wrote the draft yourself, the failure mode you should worry about is a false-positive flag, not a true-positive one. The fix for that is calibration, not score-chasing. Pre-scan with an honest detector. Look at the sentence-level highlights. Notice which rhythms read AI-shaped. Rewrite those specific sentences with the bundled ethical AI rewriter or by hand. Submit a draft that is honestly yours and that you understand the shape of. That workflow holds up regardless of which detector your institution upgrades to next quarter.
TextSight is not a tool for converting AI-generated drafts into submissions you did not write. We do not promise permanent score reduction, we do not market against integrity policies, and we do not consider the score-reduction-first workflow a problem we want to solve. If that is the tool you need, Undetectable is the more honest fit, and the rest of this page can save you from buying the wrong thing.
TextSight Starter is $9.99 a month with detection bundled. Verified .edu emails get Pro at $13.99 a month. Undetectable.ai starts around $9.99 a month for an AI rewriter-only allowance with steep annual prepay discounts. The two prices buy different things.
Billed $89.88/year, Save $30
Billed $179.88/year, Save $60
Billed $359.88/year, Save $120
Yearly billing saves 25%. Verified .edu emails get Pro at $13.99/mo, billed monthly with no annual lock-in. Undetectable.ai does not publish a student tier today. View full pricing →
You wrote a draft, you used ChatGPT to help with one section, and you want to make sure the whole thing reads honestly before Turnitin sees it. Here is the same evening with each tool, side by side.
Sign up with email, verify, paste the full essay into the AI rewriter. Pick Aggressive mode, since you have no idea which specific sentences flag and the tool does not tell you. Wait for the rewrite. Read the output and notice the voice has shifted, some technical terms got swapped, one citation got paraphrased away. Spend 20 minutes patching the rewrite by hand to restore meaning and citations. Open a separate detector tab to verify, or trust the bundled detector that exists to validate the AI rewriter's own output. Total elapsed: 45 to 60 minutes. The submitted essay reads less like you and may now have new inconsistencies a marker could question.
Paste the essay into the free scanner with no email and no signup. One scan returns the Authenticity Score, sentence-level highlights, and a Plagiarism Risk indicator. You see exactly which six sentences in your 1,500-word essay are pulling the score down, and which paragraph is the heaviest contributor. Click the bundled AI rewriter on those specific sentences in Light mode, which rewrites them in place while preserving your voice, structure, and citations. Re-scan. The score climbs from 38 to 81. Total elapsed: 15 to 20 minutes. The submitted essay still reads like you, but in a register that does not get misread as AI.
The TextSight workflow is faster because you only rewrite what is flagged, and the rewrite engine targets the same signals the detector reads. The Undetectable workflow assumes the whole essay needs rewriting because it has no way to point at specific sentences, and the most aggressive rewrite mode introduces its own marker-visible signal in the form of inconsistent voice. Both paths can get you to a passing score on a specific detector. One gets you there in a quarter of the time and leaves you with a draft that is still recognizably yours.
Both products are built by serious teams solving different problems. The honest student answer is workload-specific. Use this picker to match the tool to the workflow you actually want to be in.
If you only know one keyword and that keyword is "rewriter," Undetectable is the honest match. If your real worry is being misread as AI on work that is honestly yours, TextSight is what the calibration workflow was built for.
The full student page. .edu discount, FERPA-aware scanning, and the pre-submission workflow.
See the student page →Pre-Turnitin sentence-level scan for undergrad essays and lab reports. Perplexity and burstiness signals explained.
Read the guide →The general head-to-head across all use cases. Calibration vs score reduction, with the bigger feature table.
Read the compare →Full tier breakdown for Free, Starter, Pro and Business. Yearly billing saves 25%, .edu Pro at $13.99/mo.
See pricing →Start with TextSight's free tier. No card, no signup, no commitment. Your first scan in about six seconds, with sentence-level evidence on the work you wrote yourself.