Quillbot became a verb. Students and writers say "let me quillbot this" the way they say "let me google this." It started as a paraphraser, grew into a multi-tool writing suite covering grammar, summarization and translation, and added AI detection later as a secondary feature. TextSight came from the other direction: detection-first, AI rewriter as the rewrite layer, with paraphrasing and summarizing as supporting tools. This page is the honest comparison: where Quillbot is the right call, where TextSight wins, and what the differences look like when you scan your own content through both.
A short feature table first. The narrative sections below go deeper on each row, with the parts where Quillbot is genuinely the better call called out clearly.
| Feature | TextSight | Quillbot |
|---|---|---|
| Primary product | AI detector first, AI rewriter + plagiarism bundled | Paraphraser first, AI detector is secondary feature |
| Monthly visits (Similarweb, Apr 2026) | Growing brand | 48.1M: category leader |
| Free tier (no signup) | 3 scans/day, 5,000 chars/scan, no card | Signup required for detector; 125-word paraphrase limit on free |
| Pro monthly price | $19.99/month | $9.95/month annual (~$19.95 monthly billed) |
| Pro annual effective price | $14.99/month ($179.88/year) | $9.95/month ($119.40/year) |
| .edu student discount | $13.99/month (verified .edu) | No published .edu rate |
| Sentence-level highlights | Yes: colour-coded per sentence with per-line evidence on free tier | No: document-level score only |
| Per-sentence "why-flagged" rationale | Yes: rhythm, vocabulary, paragraph cadence, length variance | No: document-level rationale only |
| ESL false-positive rate (Indian/Filipino/Chinese student writing) | ~6% (TextSight internal benchmark, 600 ESL essays) | ~14% (TextSight benchmark of Quillbot on identical sample) |
| True-positive rate (raw GPT-4 + Claude output) | ~91% (TextSight benchmark, n=50) | ~85% (TextSight benchmark of Quillbot, identical sample) |
| Paraphraser modes | 3 AI rewriter modes (Light / Balanced / Maximum) | 7 paraphrase modes (Standard / Fluency / Formal / Simple / Creative / Expand / Shorten) |
| Grammar checker bundled | No: detection-focused | Yes: full grammar suite |
| Plagiarism database matching | Style-based Plagiarism Risk only | Database matching included (Premium tier) |
| REST API | Business $39.99/mo ($29.99 annual): 150K words/month, detection + AI rewriter + bulk | API available on higher tiers, paraphrase-focused |
| Chrome / Docs / Word integrations | Chrome extension (free), web app, paste-to-Docs | Chrome + Google Docs add-on + Word add-in (mature) |
| Best fit | Writers who need detection-first + ESL accuracy + sentence evidence | Writers who need paraphrasing + grammar suite + detection as a secondary check |
Prices, features, and benchmark numbers reflect our internal testing + Quillbot's public pricing as of . Quillbot's primary product is the paraphraser; the AI detector is a secondary free utility, which is why the comparison frames the tools as solving different jobs. "Win" markers reflect our reading of the feature gap, not a third-party audit.
Four things Quillbot does better than TextSight today. Acknowledging them is the point of writing this page in the first place.
Quillbot ships seven paraphrase modes, a strong summarizer, a grammar checker that sits in the top tier of general-purpose grammar tools, a plagiarism checker, a translator, and a citation generator. For a student rewording a stiff paragraph, a writer simplifying complex sentences, or a non-native English speaker polishing a draft, that bundle is the right shape of product. TextSight ships a Paraphraser and Summarizer tool inside the app, but Quillbot's are deeper, faster and more polished.
"Let me quillbot this paragraph" is a sentence that parses without context inside writing teams. The product has been the default paraphraser for years and the in-editor workflow is muscle memory for a lot of working writers. TextSight does the detection job and the AI rewriter job better, but the daily-driver writing assistant is still a separate question for many teams.
Quillbot ships a mature Chrome extension, a Google Docs add-on, a Microsoft Word plugin and an Edge extension. They are battle-tested across millions of users and integrate paraphrase, grammar and summarize directly inside the editing flow. TextSight ships a Chrome extension with detection plus AI rewriter inline, but the Google Docs and Word integrations are not on parity. If your team writes inside Docs or Word and wants a polish tool at the cursor, Quillbot fits.
Quillbot's free tier gives access to a 125-word paraphrase limit per session, basic grammar checking, a summarizer with capped input length, and a daily detection allowance. It is gated behind a signup, but the feature surface area is broader than most free plans on the market. TextSight's free tier is a faster path into detection specifically (no signup, 3 scans a day), but a much smaller surface area on writing-suite features.
If you fit any of those patterns, the rest of this page is informational rather than persuasive. Quillbot is the tool for the job.
For freelancers, agencies, SEO teams, editors and individual students pre-scanning their own essays, here is where TextSight beats Quillbot on the work that matters.
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 edit the specific sentences instead of rewriting the whole draft. Quillbot returns a document-level score without per-sentence breakdown, so editing means guessing which paragraphs to touch. For working writers iterating on a draft, the per-line evidence cuts editing time roughly in half on a 1,000-word piece.
Detection is the core product at TextSight, not a feature bolted on later. The classifier combines sentence rhythm, clause-structure patterns, paragraph cadence and AI-vocabulary clustering, trained against a 2025 corpus of edited and paraphrased AI output. Independent comparisons have shown Quillbot's AI detector 10 to 20 points lower than specialist tools on edited content. For decisions that affect publishing, client billing or academic submissions, the specialist gap matters.
Both tools over-flag formally-taught English from non-native writers. We tuned the TextSight classifier in 2025 against writing samples from Indian universities, Filipino education programmes and Chinese postgraduate writing. In our internal testing the false-positive rate on identical-quality essays is roughly 30 to 40 percent lower than Quillbot's detector. Quillbot's multi-language strength sits in the paraphraser and translator, not in English-ESL detection calibration.
The TextSight AI rewriter optimizes for rhythm, sentence-length variance and vocabulary-cluster removal rather than for fluency or formality. On 50 GPT-4 paragraphs the Balanced mode dropped average AI scores by 58 points; Maximum mode dropped them by 71. Running the same paragraphs through Quillbot's Fluency mode dropped scores by 22 points, Creative mode by 31. Quillbot's paraphraser is not designed for this job, and it shows on the score curve.
TextSight Pro is $19.99 monthly or $14.99 monthly on annual billing with unlimited scans, 50,000 AI rewriter words a month, file and URL upload, priority support and the Chrome extension. Verified student emails get Pro at $13.99 monthly. Quillbot Premium is roughly $9.95 monthly on annual billing for the writing suite. Quillbot's sticker is lower, but past 25,000 words a month on detection or any serious AI rewriter usage, TextSight is the better dollar on the work that matters for detection-led teams.
100-passage internal benchmark scanned through both tools the same day. Quillbot's AI detector is free + accessible, so we ran the full head-to-head with no subscription cost. Methodology + raw CSV at the bottom of this section. Re-tested quarterly.
| Passage type | n | TextSight TPR / FPR | Quillbot TPR / FPR | Notable gap |
|---|---|---|---|---|
| Raw GPT-4 output | 25 | 92% TPR | 86% TPR | TextSight +6pp TPR |
| Raw Claude (Sonnet/Opus) output | 25 | 90% TPR | 83% TPR | TextSight +7pp TPR |
| Native English human writing | 25 | 3% FPR | 8% FPR | TextSight 5pp lower FPR |
| ESL human writing (India/PH/CN) | 25 | 6% FPR | 14% FPR | TextSight 8pp lower FPR |
| Combined (all categories) | 100 | 91% TPR · 4.5% FPR | 84.5% TPR · 11% FPR | TextSight better on both TPR and FPR |
The honest read: Quillbot's detector under-performs TextSight across every category in our benchmark. That isn't because Quillbot built a bad classifier. It's because the detector is a secondary free utility on top of their paraphraser product. The 48 million people who visit Quillbot every month are mostly there for the paraphraser; the detector is a check-the-box add-on.
If you're primarily paraphrasing: Quillbot is the right tool. Their 7-mode paraphraser is the category benchmark, and the detector is "good enough" as a sanity check on your own rewrites.
If you're primarily detecting: TextSight wins by 6-8 percentage points on accuracy across all four categories. Most importantly, the 8pp ESL FPR gap (6% vs 14%) means fewer wrongful flags on non-native English writers. For agencies, teachers, and editors making content decisions, that accuracy gap compounds.
If you want both: run TextSight detection first, Quillbot paraphraser for rewrites, TextSight AI rewriter for stubborn passages. Two products, two best-in-class jobs, total cost ~$30/month combined.
The detection-method gap between TextSight and Quillbot is wider than between TextSight and other specialist detectors, because detection was never the centre of Quillbot's product roadmap.
Quillbot's AI detector launched in response to user requests after ChatGPT broke the writing-workflow assumptions Quillbot was built around. The classifier returns a document-level percent-AI score and uses signals broadly aligned with what other generalist detectors look at. It is fine for casual "is this AI?" gut checks. The honest framing is that Quillbot did not build the company around detection, and the product reflects that.
TextSight scores sentence-length variance, clause-structure patterns, paragraph cadence and how often the document leans on a small fixed set of high-frequency AI vocabulary. Paraphrasers do not fix those signals because they operate at the word level rather than the sentence-architecture level. The trade-off is that rhythm scoring needs at least four or five sentences to lock in; very short snippets are harder for the model than for token-level detectors.
Take a paragraph of raw GPT-4 output. Both tools score it within a few points of each other. Now run it through Quillbot's own Fluency mode once. Quillbot's detector typically drops by 25 to 35 points on its own paraphrased output, which is a quirk worth being honest about. TextSight's score drops by 5 to 15 points on the same content. For workflows that involve any editing pass between draft and detection, that gap matters.
TextSight Pro is $19.99 monthly or $14.99 monthly on annual billing, unlimited scans. Quillbot Premium is roughly $9.95 monthly on annual billing for the paraphraser-plus-grammar-plus-summarizer-plus-detector bundle. The two prices are not buying the same thing.
Billed $89.88/year, Save $30
Billed $179.88/year, Save $60
Billed $359.88/year, Save $120
Yearly billing saves 25%. Quillbot Premium is roughly $9.95/mo on annual billing for the full writing suite (paraphraser, grammar, summarizer, plagiarism, detector). View full pricing →
Both products are built by serious teams solving different problems. The honest answer is workload-specific. Use this picker to match the tool to the work you actually do.
If you do both workflows heavily, the honest answer is both subscriptions. Combined cost is roughly $25 to $35 a month per editor and saves more in returned-draft cycles.
Picking between a paraphraser-first suite and a detection-first specialist is workload-specific. Three concrete profiles, three concrete picks.
Wants to polish phrasing, fix grammar errors and sanity-check whether the essay reads AI before submitting. Quillbot wins for the polishing work; the grammar checker and Fluency paraphraser improve the draft inside the editor. The student then runs a separate detection check at the end through TextSight's free tier (no signup, 3 scans a day) to catch any sections that drift into AI rhythm. Two tools, both free or near-free, both used for what they are good at.
Half the drafts started as AI-assisted outlines then hand-edited. Needs to ensure each delivery reads under 30 on AI detection. TextSight wins. Detection on every draft, AI rewriter for the ones that still flag, all in one subscription at $14.99 a month on annual Pro. Quillbot's detector is not accurate enough on edited content to bet a delivery on, and the Fluency paraphraser does not reduce AI scores enough to skip the dedicated AI rewriter step.
Editorial guideline: AI score under 25 before client delivery. The agency runs both tools in tandem. TextSight on every submission for the detection pass, sentence-level highlights guiding the edit, AI rewriter on flagged drafts. Quillbot in the editorial polish stage for grammar fixes and reading-level adjustments on the drafts that pass detection. Combined cost is roughly $25 to $35 a month per editor and saves more than that in returned-draft cycles.
The full seven-tool ranking with detection accuracy, pricing and use-case fit side-by-side.
See the ranking →The classroom-detector head-to-head. ESL, perplexity and bundled AI rewriter compared.
Read the compare →How the TextSight AI rewriter differs from a paraphraser, mode by mode, with sample scores.
Read the guide →Full tier breakdown for Free, Starter, Pro and Business. Annual billing saves 25%.
See pricing →Start with TextSight's free tier. No card, no signup, no commitment. Your first scan in about six seconds.