AN HONEST COMPARISON
Noplag vs Quetext
Quetext is a popular freemium plagiarism checker with DeepSearch fuzzy matching and a Citation Assistant. Noplag adds open-source transparency, citation-aware classification, AI detection with ESL safeguards, and a developer API.
noplagOpen-source, since 2014OUR SIDE
QuetextConsumer freemium, since 2014THE STUDENT-FREEMIUM TOOL
Choose Noplag if
- You need a more generous free tier — Quetext caps free at 500 words/report · 3 reports/month; Noplag is 2,500 words/check, unlimited
- You need API access for content pipelines — Quetext doesn't expose a public REST API
- You need to see the matching algorithm — Apache 2.0 source vs Quetext's closed DeepSearch
- You need self-host for confidential drafts — Quetext is SaaS only
- You need citation-aware classification — Quetext over-flags properly-cited APA papers at 30% (independent test); Noplag classifies quoted/paraphrased/uncited
- You need serious AI detection (coming soon) — Quetext added AI detection as a side feature; Noplag's documented Binoculars methodology with ESL calibration is on the roadmap
Choose Quetext if
- You like ColorGrade visualisation — Quetext's colour-coded plagiarism severity is genuinely well-designed
- You use the Citation Assistant — Quetext auto-generates MLA / APA / Chicago citations for every matched source
- You only check short documents — the 500-word free cap covers typical class submissions
- You want bulk upload — Quetext's Essential plan supports 20-file batch uploads
- You're using the AI Summarizer — Quetext bundles 25k words/mo of summarisation alongside plagiarism
- Brand familiarity matters — Quetext has been in this space since 2014, like Noplag, and many students recognise it
FEATURE COMPARISON
The actual differences, line by line.
ACCESS & CONTRACTS
Individual access
NOPLAGYes · sign up in 30 seconds
QUETEXTYes · Free tier or Essential subscription
Pricing model
NOPLAGFlat-rate · $0 / $23 / $79 / Custom
QUETEXTFree · Essential $15.99/mo · Enterprise $14.99/mo
Free tier
NOPLAG2,500 words/check · unlimited checks
QUETEXT500 words/report · 3 reports per month
Paid monthly volume
NOPLAGPremium · 50,000+ words/check, unlimited checks
QUETEXTEssential · 100,000 words/month total
Procurement complexity
NOPLAGCredit card · self-serve
QUETEXTCredit card · self-serve
DETECTION & ACCURACY
Auditable algorithm
NOPLAGApache 2.0 source on GitHub
QUETEXTClosed source · DeepSearch is proprietary
Open-web check
NOPLAGGoogle + Brave + Common Crawl
QUETEXTDeepSearch index · “billions of documents”
Scholarly database
NOPLAGOpenAlex + CORE + arXiv + PMC · 700M+ open-access
QUETEXTNot specifically academic-focused
Citation classification
NOPLAGQuote / Paraphrase / Common knowledge / Unattributed
QUETEXTCitation Assistant (auto-generates citations)
False-positive rate published
NOPLAGMeasured against PAN-PC-11 in CI
QUETEXTNot disclosed · 30% reported on properly cited APA (independent test)
AI-CONTENT DETECTION
AI detection available
NOPLAGComing soon · ESL-adjusted
QUETEXTYes · Essential add-on (recent feature)
AI detection method
NOPLAGBinoculars ensemble (Hans et al. 2024, open paper)
QUETEXTProprietary · methodology not disclosed
ESL-bias safeguard
NOPLAGPer-language calibration + ESL-adjusted verdict
QUETEXTNot addressed publicly
Per-interval transparency
NOPLAGPer-sentence · interval-level drill-down
QUETEXTColorGrade severity bands · summary view
PRIVACY & DATA
Documents used to train models
NOPLAGNever · explicit policy
QUETEXTNot used for training (per policy)
Right-to-erasure (GDPR)
NOPLAGOne-click in Settings
QUETEXTAccount-deletion flow
EU data residency
NOPLAGAvailable · Premium+
QUETEXTNot specifically offered
Self-host / on-premise
NOPLAGYes · Apache 2.0 engine + Docker
QUETEXTNo · SaaS only
DEVELOPERS & INTEGRATIONS
Public REST API
NOPLAGYes · OpenAPI 3.0 · $23/mo+
QUETEXTNo public REST API
Webhooks
NOPLAGYes · Premium+
QUETEXTNo
Bulk upload
NOPLAGFolder-level scan (Premium tier)
QUETEXT20-file batch upload (Essential tier)
Multilingual coverage
NOPLAGEnglish, Spanish, Portuguese, Polish, Ukrainian · expanding
QUETEXTEnglish-primary
| Feature | NOPLAG | QUETEXT |
|---|---|---|
| ACCESS & CONTRACTS | ||
| Individual access | Yes · sign up in 30 seconds | Yes · Free tier or Essential subscription |
| Pricing model | Flat-rate · $0 / $23 / $79 / Custom | Free · Essential $15.99/mo · Enterprise $14.99/mo |
| Free tier | 2,500 words/check · unlimited checks | 500 words/report · 3 reports per month |
| Paid monthly volume | Premium · 50,000+ words/check, unlimited checks | Essential · 100,000 words/month total |
| Procurement complexity | Credit card · self-serve | Credit card · self-serve |
| DETECTION & ACCURACY | ||
| Auditable algorithm | Apache 2.0 source on GitHub | Closed source · DeepSearch is proprietary |
| Open-web check | Google + Brave + Common Crawl | DeepSearch index · “billions of documents” |
| Scholarly database | OpenAlex + CORE + arXiv + PMC · 700M+ open-access | Not specifically academic-focused |
| Citation classification | Quote / Paraphrase / Common knowledge / Unattributed | Citation Assistant (auto-generates citations) |
| False-positive rate published | Measured against PAN-PC-11 in CI | Not disclosed · 30% reported on properly cited APA (independent test) |
| AI-CONTENT DETECTION | ||
| AI detection available | Coming soon · ESL-adjusted | Yes · Essential add-on (recent feature) |
| AI detection method | Binoculars ensemble (Hans et al. 2024, open paper) | Proprietary · methodology not disclosed |
| ESL-bias safeguard | Per-language calibration + ESL-adjusted verdict | Not addressed publicly |
| Per-interval transparency | Per-sentence · interval-level drill-down | ColorGrade severity bands · summary view |
| PRIVACY & DATA | ||
| Documents used to train models | Never · explicit policy | Not used for training (per policy) |
| Right-to-erasure (GDPR) | One-click in Settings | Account-deletion flow |
| EU data residency | Available · Premium+ | Not specifically offered |
| Self-host / on-premise | Yes · Apache 2.0 engine + Docker | No · SaaS only |
| DEVELOPERS & INTEGRATIONS | ||
| Public REST API | Yes · OpenAPI 3.0 · $23/mo+ | No public REST API |
| Webhooks | Yes · Premium+ | No |
| Bulk upload | Folder-level scan (Premium tier) | 20-file batch upload (Essential tier) |
| Multilingual coverage | English, Spanish, Portuguese, Polish, Ukrainian · expanding | English-primary |
PRICING REALITY
Flat-rate vs monthly-word-quota.
Quetext pricing direct from quetext.com/pricing, May 2026. Word-based monthly caps with a bundled AI Summarizer. Noplag is flat-rate — pay once a month, scan up to your tier limit.
noplagMOST FLEXIBLE
- Free / self-host$0Apache 2.0 forever
- Pro$23/moyearly · 500 pages/mo
- Premium$79/moyearly · 5,000 pages/mo
- EnterpriseCustomannual · unlimited pages
QuetextCONSUMER FREEMIUM
- Free$0500 words · 3 reports/mo
- Essential$15.99/mo100k words/mo · Summarizer
- Enterprise$14.99/moper-seat · team accounts
- Add-onsvariesextra words · bulk pack
Quetext pricing direct from quetext.com/pricing, May 2026. Free tier is heavily capped at 500 words/report, 3 reports/month.
WHEN QUETEXT IS THE RIGHT CHOICE
If you check short documents occasionally and want a familiar consumer UI, Quetext is fine.
Quetext built a polished consumer freemium UI with ColorGrade severity highlighting and an integrated Citation Assistant that auto-generates citations — both genuinely useful for student-volume use. Noplag isn't trying to win on the consumer-freemium UX dimension. We compete where the workflow needs more: serious AI detection with ESL safeguards, citation-aware classification (not just generation), API + self-host, multilingual coverage, and the cascade that catches paraphrasing without flagging the common-industry-phrase false positives Quetext is known for.
Read the workflow comparisonFREQUENTLY ASKED
Questions from students comparing the two.
- Will Quetext's free tier cover a typical class essay?
- A typical class essay is 1,500–2,500 words; Quetext's free tier caps at 500 words/report. So usually no — you'd need to split the essay into chunks or upgrade to Essential. Noplag's free tier covers 2,500 words/check with unlimited checks, which fits the typical essay length without splitting. For longer papers (research papers, theses) both require the paid tier.
- What's DeepSearch and how is it different from Noplag's cascade?
- DeepSearch is Quetext's proprietary fuzzy-matching algorithm that catches paraphrased content; the methodology isn't disclosed. Noplag uses a four-layer cascade (winnowing fingerprints → MinHash LSH → vector embeddings → live web verification) — all open-source, each layer documented in the github.com/NoplagLabs/noplag-engine repo. Both catch fuzzy matches; only one shows how.
- Is the 45% common-phrase false-positive issue real?
- It's the most-cited Quetext criticism in independent reviews. Industry-standard terminology (“engagement rate”, “conversion funnel”, “abstract”) flags as plagiarism because DeepSearch doesn't classify common knowledge separately. Noplag's report classifies every matched interval — Direct quote / Paraphrase / Common knowledge / Unattributed — so the headline similarity number reflects what's actually problematic.
- Does Quetext's Citation Assistant generate citations like a built-in formatter?
- Yes — Quetext auto-generates MLA / APA / Chicago citations for every matched source. It's a genuine convenience feature, especially for first-year students. Noplag doesn't generate citations; we classify existing ones (was a citation present and correctly formatted? what style?). Different philosophy: Quetext writes the citation for you; we tell you whether yours is OK.
- How is the AI detection comparison?
- Quetext added AI detection as a recent Essential-tier feature with undisclosed methodology. Noplag's AI detection is coming soon — it will use Binoculars (Hans et al. 2024, open paper) with per-language calibration and a documented ESL-bias adjustment. If AI detection is a peripheral feature for you, Quetext's is adequate today. For integrity-board-level defensibility, the methodology citation is what matters.
- Can I self-host Quetext for confidential drafts?
- No — Quetext is SaaS-only. Noplag's engine is Apache 2.0 + Docker, runs entirely inside your network. Useful for sensitive research drafts, unpublished manuscripts, or institutional setups where student documents can't go to a third-party cloud.
- Does Quetext have an API?
- Not a public REST API for plagiarism. Quetext exposes its tooling through the web app and the Essential subscription. Noplag has a REST + OpenAPI 3.0 spec, Python and Node SDKs, webhooks (Premium+), and a $23/mo Pro tier specifically for embedding plagiarism checks in your own product or content pipeline.
Try the same draft in both. See the citation classification.
Drop a draft that Quetext flagged into Noplag. The headline similarity number will differ — what changed is the classification. The properly-cited intervals don't inflate the score; the genuinely uncited paraphrases stay flagged. Free up to 2,500 words. The difference between “matched” and “plagiarism” is the whole point.