NEWv5.0 is live — open-core

The plagiarism checker you can audit.

Open-source engine, multilingual corpus, live-web verification. Trusted by 12,000 writers, researchers, and educators since 2014.

0 / 1,500 words
No signup requiredApache 2.0 engineReports in under 1 minute
TRUSTED BY RESEARCHERS AND PUBLISHERS WORLDWIDE
StanfordHarvardMITOxfordCambridgeETH ZürichUCL
The New York TimesThe GuardianPenguin Random HouseSubstackMediumHarperCollins
HOW IT WORKS

Three steps from upload to highlighted report.

No accounts to set up, no API keys to manage. Drop a document, get a report, see exactly which passages match which sources.

  1. 01

    Submit your document

    Upload .docx, .pdf, .txt, .odt, .rtf, paste text directly, or submit a URL. Up to 2,500 words on the free tier, 50,000+ on paid plans.

  2. 02

    We compare against 150M+ documents

    Live web search, academic papers, Common Crawl, Wikipedia, the Noplag Database, and your own past work.

  3. 03

    Read the highlighted report

    Every matched passage shows the source URL, similarity score, and the exact overlapping text. Export PDF, share, or save to a folder.

BUILT TO BE AUDITED

An engine you can read, fork, and run yourself.

Every plagiarism checker before us has been a black box. We're the first that isn't.

Apache 2.0 engine

Read the source. Fork it. Self-host. The shipping detection engine — winnowing fingerprints, alignment, and report assembly — lives on GitHub. MinHash LSH and vector reranking land there as they ship.

Multilingual

Fingerprint matching is language-agnostic, so it works on any script, and the corpus spans many languages. The interface ships in 19 languages.

AI-content detection (coming soon)

Binoculars-based ensemble with ESL-bias safeguards, on the roadmap. When it rolls out it'll be reported as a separate signal, never conflated with plagiarism.

Privacy-first

Documents stay yours. Never used for training. EU residency available. Right-to-erasure for every fingerprint we hold.

Five corpora, one report

Live web · Common Crawl · Wikipedia · academic papers · Noplag Database · your own folders. Toggle any combination.

Developer API

REST + OpenAPI spec, webhooks, 5 API keys included on Pro plans. Same engine that powers the dashboard.

THE REPORT

Every check, every source, every match. Organized.

A similarity score up top, every flagged passage highlighted inline, and each match linked back to its source. Export to PDF in two clicks.

noplag.app/report
noplag
31%
Checked 2 minutes ago606 words6 sources found7 flagged passages

Untitled document

Submitted May 18, 2026 at 14:32

Climate change presents one of the most pressing challenges of the twenty-first century. Across continents, communities are confronting rising temperatures, shifting weather patterns, and the increased frequency of extreme events. Scientists overwhelmingly agree that human activity, particularly the burning of fossil fuels, is the primary driver of these changes.

Anthropogenic greenhouse gas emissions have increased atmospheric carbon dioxide concentrations by roughly fifty percent since the start of the industrial era.1 The consequences are visible in melting polar ice, ocean acidification, and the displacement of millions of people from coastal regions.

Policymakers face the difficult task of balancing economic growth with environmental responsibility. Recent international agreements aim to limit warming to 1.5 degrees Celsius above pre-industrial levels, though implementation remains uneven across nations.

Renewable energy adoption has accelerated dramatically over the last decade, with solar and wind capacity now competitive with traditional fossil sources in many regions. The transition will require unprecedented coordination across sectors and continents.2

Adaptation strategies, equally important, must address the impacts that are already locked in. Coastal infrastructure, agricultural systems, and public health frameworks all require rethinking in light of a warmer, more volatile climate.

Education and informed civic engagement remain among the most powerful tools available. Without sustained public understanding of the science and the stakes, political will tends to drift toward shorter-term concerns.3

The economics of decarbonization have shifted markedly in the past five years.4 What were once framed as costly sacrifices are increasingly understood as investments with measurable returns, from reduced air-pollution mortality to the industrial advantage of leading on clean technology. Capital markets have begun to price climate risk into long-term assets, and that repricing is reshaping where money flows.

Yet the transition is uneven. Wealthier nations, having contributed the bulk of historical emissions, retain the fiscal and technological capacity to adapt; many lower-income countries face the sharpest impacts with the fewest resources. Questions of climate finance, technology transfer, and loss-and-damage compensation now sit at the center of every major negotiation, and progress on them has been halting at best.

Cities have emerged as unexpectedly decisive actors. Home to more than half the world's population and the majority of its emissions, urban centers control the levers that matter most: building codes, transit systems, zoning, and procurement.5 A growing network of mayors has moved faster than national governments, treating climate policy as a question of livability rather than abstraction.

The land sector complicates the picture further. Forests, wetlands, and soils store vast quantities of carbon, and their degradation releases it.6 Protecting and restoring these systems offers some of the cheapest available mitigation, but it competes directly with agriculture, development, and extraction. Aligning conservation with the livelihoods of the people closest to these landscapes remains an unsolved problem.

Technology will not substitute for governance, but it changes what governance can achieve. Cheaper storage, smarter grids, and advances in materials science widen the set of politically feasible options. The danger lies in treating any single breakthrough as a reason to defer the harder work of building institutions that can deploy it at scale.

Public sentiment, long assumed to be a brake on ambitious policy, has proven more malleable than expected.6 Direct experience of extreme weather, combined with the falling cost of alternatives, has shifted majorities in many countries toward support for stronger action — provided the burdens are seen as fairly shared.

None of this guarantees success. The trajectory of emissions still points toward warming well above the thresholds scientists describe as safe. But the question has quietly changed from whether a transition is possible to how quickly and equitably it can be managed, and that shift, however incremental, marks real progress.

  • 12,000writers
  • 150M+documents in corpus
  • 42saverage check time
  • 5languages at launch
  • 2014year established
WHY NOPLAG

What black-box checkers can't say.

TURNITIN

Institutional contracts only. 5-year lock-ins. No individual access. AI detector disabled by Yale, Hopkins, Northwestern.

Pay-as-you-go from $0. Cancel any time. An open-source engine you can audit or self-host.

COPYLEAKS

12% false positive rate on human text in independent tests. Opaque scoring. No way to audit how the score is generated.

Open-source scoring. Every match shows source URL, similarity score, and exact overlapping text. Auditable end-to-end.

ORIGINALITY.AI

English-only. Credit-based pricing that gets expensive at volume. No self-host option for privacy-conscious orgs.

Multilingual detection across English, Spanish, Portuguese, Polish, and Ukrainian at launch, with more rolling out. Flat-rate plans with usage transparency. Self-host the engine for free.

ESTABLISHED 2014

Twelve years of plagiarism detection. One open-source rebuild.

Noplag started as a free plagiarism checker in Kyiv in 2014. We joined a New York EdTech accelerator in 2018, raised $200K, served over a million checks, then stepped back to rethink the architecture. Today we're headquartered in San Francisco with engineering across Ukraine, Poland, and Spain. v5.0 is what we wished we'd built from the start: open-source engine, anonymized-fingerprint corpus, and an honest privacy posture.

Read our full story
RECOGNITION & REVIEWS

Over a decade of keeping writing original.

Since 2014, Noplag has helped students, educators, publishers and businesses check their work against a corpus of 150M+ web pages, academic publications and private libraries — and it's earned a place among the names the industry tracks.

Industry recognition

Profiled alongside the field's leading names.

Independent market-research firms name and profile Noplag as a recognized vendor in the global plagiarism-detection software market — in the same company as the industry's biggest players.

TurnitinGrammarlyCopyleaksQuetextScribbrOriginality.ai

What people say after they switch.

Verified reviews · public platforms

I've tried many plagiarism checkers for grading. Noplag found most of the matches in students' work — and I could submit 20 assignments at once and get results on each in a couple of minutes.
College Instructor
Higher education · checks student submissions
via Sitejabber
It checks quotes, paraphrasing and the original source. It even found duplicate content on my site and saved me extra work.
Pallav Singh
Marketing Manager
via TrustRadius
Working as a copywriter, I need an accurate checker. Noplag's results have always matched what my clients require — and My Library keeps all my texts in one place.
Eva B.
Copywriter
via Sitejabber
Extremely flexible — you can exclude citations and even set how many consecutive words count as a match. Uploads DOC, DOCX, PDF, HTML and more.
Stanley Kamal
Software Engineer
via TrustRadius
An excellent tool for checking academic or business papers — extremely easy to use, and it scans a document in under 30 seconds. One of the best plagiarism detectors out there, with the minimum of fuss.
Verified Reviewer
Business & academic writing
via TrustRadius
Listed & reviewed on

Recognition reflects Noplag's inclusion as a profiled vendor in independent market-research reports and its listings across major software-review platforms. Testimonials are drawn from public reviews and lightly edited for length.

PRICING

Start free. Pay only when you outgrow it.

Free

Try it, or self-host

$0
Start free

Pro

For makers + small teams

$23/mo
Start 14-day trial
MOST POPULAR

Premium

For agencies + publishers

$79/mo
Start 14-day trial

Enterprise

Universities + regulated orgs

Custom
Contact sales
See full pricing comparison

Check your first document in under a minute.

No card. No signup wall. The free tier runs forever — paste up to 2,500 words and see the report shape before you decide anything.

FAQ

What people ask before they check.

Is Noplag free?

Yes. The free plan gives you 3 checks a month, up to 2,500 words each, with no card required. Because the engine is open-source (Apache 2.0), you can also self-host it and run unlimited checks locally. Paid plans — Pro at $23/mo and Premium at $79/mo — add the cloud corpus and higher limits.

Does Noplag detect AI-generated text, and how accurate is it?

Plagiarism checking is live today, and every match links to its source so you can verify it yourself. AI-generated-text detection is coming soon — it's on our roadmap and rolling out alongside plagiarism checks. We treat AI detection as a signal, not a verdict, and we'll publish our false-positive rates for non-native English writing, which most detectors over-flag.

Are my documents stored or used to train AI?

No. Your documents are never used to train AI models. By default, submitted documents are added to the Noplag Database to improve cross-submission matching, but you can opt out at any time. Data retention is configurable, EU data residency is available on request, and you can delete anything you've checked at any time. Your work stays yours.

What does Noplag check against?

Your text is compared against the live web, Common Crawl, Wikipedia, and academic sources. Paid plans add cross-submission matching against your own document history, and Premium adds real-time Live Web search — checking the most current pages, not just an index.

How is Noplag different from Turnitin or Copyleaks?

Noplag is the only plagiarism checker with both a production cloud service and a fully open-source engine you can audit or self-host. It offers plagiarism checking at a flat monthly price — with AI detection on the roadmap — and no institutional contract. Your documents are added to our shared database by default to improve matching, and you can opt out at any time.

Noplag — the plagiarism checker you can audit