
Glasp
Glasp is a social highlighter for web pages, PDFs, YouTube and Kindle, aimed at researchers, students and writers. Its extension, web app and mobile apps turn saved passages into a personal AI memory you can question. Free to start.
What is Glasp?
Glasp, short for Greatest Legacy Accumulated as Shared Proof and pronounced like “clasp”, is a social web and PDF highlighter wrapped around an AI learning assistant. It was founded in June 2021 by Kazuki Nakayashiki and Kei Watanabe, and is operated from San Francisco by Glasp Inc. Its origin is unusually specific: after a subdural hematoma, Nakayashiki was struck by how much accumulated knowledge dies inside private notebooks, and built a product on the opposite premise.
The workflow runs in three stages the company calls Highlight, Organize, Recall with AI. You underline passages on web pages, PDFs, YouTube videos, Kindle books, audio files and images; everything lands in one searchable library sorted by tag and by author; then a personal AI trained on your own highlights, not on the whole internet, answers questions about what you have read. That AI clone is the center of gravity of the product, and other people can consult it too.
The social bet is the design decision that defines Glasp: highlights are public by default, and private highlighting is a paid feature. That is what produces the community knowledge graph, where you can find who underlines the same subjects as you, and it is also why adopting Glasp means deciding deliberately what you underline.
Around this sit the connections. A free MCP connector exposes the library to Claude, ChatGPT, Claude Code and the OpenAI API through nine tools, eight of them read-only. A public REST API on api.glasp.co uses Bearer authentication at 100 requests per minute. Extensions cover Chrome, Safari, Edge, Brave, Firefox and Opera, alongside iOS and Android apps rebuilt in 2026.
The scale claimed is large: more than 2,000,000 users, a 4.5 Chrome Web Store rating shown on the homepage (4.7 across 4,267 reviews in the site's structured data), coverage cited from Forbes, The Guardian, Business Insider, Entrepreneur, Lifehacker, MakeUseOf and Nikkei, and seven arXiv papers published with reproducibility bundles. The perimeter has edges, though: no OCR, so scanned PDFs are out of reach, and the extension stays deliberately switched off on banking, sign-in, password-manager, tax, immigration, health and adult sites.
What it does
- Highlight text on any web page or PDF, in several colors, with notes attached
- Ask your own library in plain language through the AI clone built on your highlights
- Summarize a YouTube video with AI and pull its transcript
- Upload PDFs, summarize them, then chat with the document
- Import Kindle highlights and resurface them in a daily review
- Connect your highlights to Claude or ChatGPT through the MCP connector
- Export everything to Notion, Obsidian, Roam, Markdown, CSV or JSON
When to use Glasp / When not to
A quick filter to help you decide if Glasp is the right fit.
When to use Glasp
- Researchers who collect evidence across papers and web articles, then question their own library instead of re-reading everything
- Students turning lecture material, PDFs and YouTube videos into revisable notes, with a daily review habit and a 40% education discount
- Writers and content creators building a quote file they can pour straight into Notion or Obsidian
- Teachers and educators, who get the same 40% discount and can hand out a highlight link that opens without a login
- Long-haul self-learners who want a personal corpus that stays alive through AI recall and through the highlights other readers make public
When not to use Glasp
- Anyone working from scanned PDFs: there is no OCR, so an image of text offers nothing to select
- Readers who open documents in a desktop PDF application, or who need to highlight text sitting in a canvas or a cross-origin iframe, which browsers do not allow
- People who need notes to be private by default: highlights are public unless you pay for a private-highlighting tier
- Regulated or enterprise buyers: there is no DPA, no published sub-processor list and no security certification, and pricing has no team plan
- Phone-first readers expecting a mobile browser extension: there is none, and everything goes through the app's own reader
How to use Glasp
A typical end-to-end flow, from setup to results.
- Install the extension from the Chrome Web Store, the App Store for Safari, Edge Add-ons or Firefox Add-ons, or simply create an account on glasp.co
- Reload any page that was already open before the install, otherwise the extension will not activate on it
- Select text on a page or in a PDF, click to highlight, and add a note where context matters
- Watch everything land in a single library, searchable and sortable by tag and by author
- On YouTube, generate an AI summary with the transcript, and highlight passages with their timestamps
- Bring your existing archive in from Kindle, Readwise, Matter, Medium, Instapaper, Hypothesis, Raindrop.io, Weava, Diigo, Wallabag, Airtable, Pocket or Snipd, or from a CSV using the column mapper
- Sign in to the same account on the site and in the extension, otherwise paid features will not appear
- Question your library through the AI clone, or plug it into Claude or ChatGPT via MCP, using OAuth on the web or a token for Claude Code and the OpenAI API
- Add the home-screen widget to keep the daily review going
- Export whenever you want to Notion, Obsidian, Readwise, Roam, Zotero, Tana, Workflowy, Anki, Markdown or CSV
Pros & Cons
Pros
- One tool covers web pages, PDFs, YouTube, Kindle and audio, instead of one app per format
- The free tier is genuinely usable for a regular reading habit and asks for no payment card
- Export is not paywalled: ten destinations plus Markdown, CSV and JSON, so nothing holds your highlights hostage
- Thirteen import sources, including a CSV column mapper for archives it does not natively recognize
- The MCP connector is included at no cost and read-only by default, and the public REST API is documented
- The extension publishes an explicit list of site categories where it refuses to run: banking, sign-in and SSO, password managers, tax and immigration portals, health records and adult sites
- Self-service cancellation and account deletion, a 40% discount for students and educators, extensions on six major browsers and iOS and Android apps rebuilt in 2026
Cons
- Highlights are public by default, and keeping them private requires a paid subscription
- No data processing agreement is published or offered, and there is no sub-processor list, only categories of service providers with Stripe and Google Analytics named
- No security certification is displayed, neither SOC 2 nor ISO 27001
- The privacy policy says nothing about training AI models on customer data, for or against, and no training opt-out is documented
- Retention is described only through qualitative criteria, with no figure and no purge deadline after deletion, and Do Not Track signals are not honored
- Data is hosted in the United States with no European residency option, and no Article 27 GDPR representative is appointed despite a dedicated GDPR section
- Pricing is strictly individual, with no team or enterprise plan, no lifetime offer, and no refunds beyond legal obligation even on automatic renewal, while the legal documents have not changed since 2024
Pricing & Plans
Glasp operates on a freemium basis. A permanent free plan is available and requires no payment card; it is a free tier rather than a time-limited offer. The lowest paid entry point is the Pro plan at 12.50 USD per month, or 150 USD per year on an annual commitment, against 180 USD when the same plan is paid monthly. The Unlimited plan is priced at 30 USD per month or 360 USD per year. Prices are stated in USD and taxes may apply. Billing is recurring and renews automatically, payments are handled by Stripe, and amounts are non-refundable except where the law requires otherwise. A subscription may be canceled at any time, with access retained until the end of the paid period. No lifetime offer is proposed.
- unlimited public highlights
- 3 basic YouTube summaries per day
- 1 tracked channel (3 videos)
- 30 PDF files
- 20 PDF Chat messages per month
- 20 AI credits per month on the Fast model
- and 30 minutes of audio transcription per month
- unlimited private highlights
- unlimited basic YouTube summaries
- 1
- 000 advanced summaries per month
- 5 tracked channels (30 videos)
- 100 PDF files
- 500 PDF Chat messages per month
- 500 AI credits per month across all models
- 5
- 000 advanced summaries per 30 days
- 25 tracked channels (500 videos)
- unlimited PDF files
- 5
- 000 PDF Chat messages per month
- 2
- 000 AI credits per month
Data, GDPR & hosting
A consolidated view of how Glasp handles your data.
GDPR overview
The privacy policy, last updated on 2 August 2024, carries a dedicated GDPR Compliance section covering the EEA and Switzerland; the terms of service have been in force since 28 February 2024. Users are granted access, rectification, erasure, restriction, objection, portability and withdrawal of consent, plus the right to complain to a supervisory authority in the EEA or the United Kingdom. Personal data from EU users is transferred to the United States, where the servers sit, under standard contractual clauses approved by the European Commission, with EU user consent given as the declared basis. What is missing is equally concrete: no Article 27 representative, no named DPO (hi@glasp.co is the single contact), no data processing agreement, no sub-processor list and no SOC 2 or ISO 27001 certification. The service is not intended for under-13s, and browser Do Not Track signals are explicitly not honored.
Who owns the data?
Glasp Inc., 548 Market St, PMB 26241, San Francisco, is the data controller for the purposes of the GDPR. What you produce stays your material: titles, metadata, tags, highlights and annotations are handled as Customer Content, and export is deliberately not a paid feature, covering Notion, Obsidian, Readwise, Roam, Zotero, Tana, Workflowy, Anki, Markdown and CSV. The caveat is exposure. Anything you publish through the public parts of the service is treated as public, falls outside the privacy policy's protections and can be indexed by search engines, and your profile, name, username and social handle are shared publicly. Deleting your account is self-service, removes highlights, favorites, summaries and profile, and is irreversible.
Reuse rights
Glasp states what it collects data for: running the service, billing, support, security, fraud prevention, research and development, audience measurement and product communications, with legitimate interest invoked for R&D, security and fraud prevention. Recipients are described by category rather than by name: service providers, the organization a user belongs to, the public, authorities, and an acquirer in the event of a merger or sale. Two providers are named: Stripe processes payments, so card details never reach Glasp, and Google Analytics measures audience, with opt-out through Google's own tool. De-identified and aggregated data falls outside the policy. Under the CCPA, Glasp states it does not sell the personal information of California residents, and the policy rules out automated decision-making or profiling producing legal effects without human intervention. One silence matters for anyone reusing their own material: the policy never addresses whether customer data is used to train AI models, in either direction, and documents no training opt-out, even though the site's robots.txt sets ai-train=no for its own published content.
Data retention & training
Hosting summary
Glasp's servers are located in the United States, and the privacy policy states plainly that information processed by the company may be transferred, processed and stored anywhere in the world. Personal data collected from EU users may therefore leave the EEA for the United States; Glasp declares that such transfers comply with the GDPR, for instance through standard contractual clauses approved by the European Commission. No European data residency option is offered, and no additional hosting country or region is named, so a buyer who needs data to remain in the EEA has no setting to reach for. Two providers sit alongside that hosting: Stripe processes payments, meaning card data never reaches Glasp's own systems, and Google Analytics handles audience measurement, with opt-out available through Google's own tool. Beyond those two, the policy describes only categories of service providers rather than a named sub-processor list, and no hosting-related certification such as SOC 2 or ISO 27001 is displayed.
Things to keep in mind
Risks and trade-offs to weigh before adopting Glasp.
- Highlights are public by default, so underlining a sensitive document makes it discoverable, and it is easy to forget which mode you are in
- Anything made public leaves the scope of the privacy policy and can be indexed by search engines, and your profile, name, username and social handle are published alongside it
- No retention period is quantified and no purge deadline is stated once an account is closed, so export before deleting: the deletion itself cannot be undone
- No training opt-out is documented and the policy never states whether your data feeds model training, so you cannot rely on a commitment that was never made
- Data is transferred to and stored in the United States, and browser Do Not Track signals are ignored
- Subscriptions renew automatically and are non-refundable, so cancellation has to happen before the renewal date rather than after it
- The legal documents date from 2024 while the product changed through 2026, and a single mailbox handles legal, GDPR, support and copyright requests alike
Setup & Integrations
Technical difficulty
Low for everyday use. The extension installs in one click from the browser store, and highlighting can start before an account exists. Two frictions are documented: a page already open when you install must be reloaded before the extension activates, and paid features only appear if you are signed in to the same account on the site and in the extension. Developer setup stays modest: MCP connects Claude and ChatGPT through one-click OAuth, while Claude Code and the OpenAI API use a personal token, as does the REST API with standard Bearer calls.
Deployment
Apps stores
Integrations
Supported languages
Behind Glasp
Social
Resources
All the official URLs gathered for verification and reference.
Alternatives
Tools that compete with or complement Glasp.
Frequently asked questions
What does the name Glasp mean?
Is Glasp free to use?
Are my highlights private?
What can I highlight, and on which devices?
Can I get my highlights out, and bring existing ones in?
Is there an API?
Does Glasp work on every page?
Where is my data hosted?
Can I get a refund if I cancel?
How do I delete my account?
Should you pick Glasp?
Glasp is a mature and unusually broad product for individual use: one tool, and often no subscription at all, covers web pages, PDFs, YouTube, Kindle and audio, a range of formats few competitors match at this price. The free tier is enough for a regular reading habit, and because export to ten destinations plus Markdown, CSV and JSON is not paywalled, the risk of ending up locked in is low. The free MCP connector and the public REST API reinforce that, since the library remains usable outside Glasp.
The public-by-default choice is the first thing to weigh. It is a design position rather than an oversight, since the community knowledge graph only exists because highlights are shared, and private highlighting is precisely what the paid tiers sell. That works for public reading and fits poorly with sensitive documents or anything you would rather not see indexed.
For an organization, the picture is harder. The legal documentation trails the product: the privacy policy has not changed since August 2024 and the terms since February 2024, while the product moved considerably through 2026. There is no data processing agreement, no published sub-processor list and no SOC 2 or ISO 27001 certification. Hosting is American with no European residency option, no Article 27 representative is appointed, and retention is described in qualitative terms only.
The point most worth checking before committing is the silence on model training: the privacy policy never says whether customer data feeds AI training, in either direction, and documents no opt-out. For a personal reading and recall habit, Glasp is an easy recommendation. For a regulated purchase, put those questions in writing first, keeping in mind that hi@glasp.co is the only channel, for legal, GDPR and support alike.
- Choosing a selection results in a full page refresh.
- Opens in a new window.