CryptPad is an open-source (AGPL-3.0-or-later), end-to-end encrypted collaborative office suite that runs entirely in the browser — rich text, spreadsheets, code/markdown, kanban, slides, forms and a whiteboard — developed by a team at XWiki SAS, a Paris-registered independent software company, and offered on a flagship instance (cryptpad.fr) plus a directory of unaffiliated third-party public instances. Its documentation states that no email address is required to register, that documents and account data are encrypted client-side so instance administrators cannot read them or reset passwords, and that what the server does see is the user's IP address, user agent and a random public signing key. The project publishes a cryptographic whitepaper and an explicit honest-but-curious threat model that concedes the central caveat of a web-delivered client: users must trust the instance to serve unmodified JavaScript, and an instance operator can be compelled to hand over its (encrypted) database and logs. Development has been funded by French and EU grants (BPI France, NLnet, NGI TRUST/DAPSI, Mozilla Open Source Support), cryptpad.fr subscriptions and donations. Affirmative security artifacts include a BSI-commissioned audit by Uni Systems (disclosed June 2026), a European Commission-sponsored Intigriti bug bounty in early 2022, and a formal security policy requiring CVEs; the flagship suffered a roughly three-hour denial-of-service outage on 28 January 2026 that the team documented in a public post-mortem. No data breach or regulatory action involving CryptPad was found.
TIMELINE
NO ENTRIES ON FILE YET.
TOOLS WE RECOMMEND
PLUS
RECEIPTS
16 ON FILE
COLLECTION
The documentation FAQ for the flagship instance states that, as a company registered in France, the operator is legally required to collect a name, postal address and email address from paying subscribers for invoicing and subscription communication — the one place identity data enters an otherwise pseudonymous account model; the same FAQ states administrators are assumed honest-but-curious and that share links should be treated as sensitive as a passphrase.
CryptPad's user guide states that registration does not require an email address — the username is an arbitrary string that instance administrators cannot see and that is never used to contact the user — and that administrators cannot view, retrieve or reset a lost password, so no password-reset email flow exists.
The user guide's security page states that CryptPad's server has no access to document content but that the chosen instance can see the user's IP address and user agent, describing this as only a weak form of anonymity and recommending Tor for stronger guarantees; it also lists the trust assumptions — that the instance runs the published code and follows its own terms and privacy policy.
The CryptPad repository's LICENSE file is the GNU Affero General Public License version 3, so both the client and the server code that any instance runs are published under a copyleft licence and can be inspected, audited or self-hosted.
XWiki's legal notice identifies the operating company as XWiki SAS, capitalised at 38,160 euros, registered in the Paris Trade and Companies Register under number 477 865 281, headquartered at 4 Rue du Faubourg Poissonnière, 75010 Paris, with Ludovic Dubost named as CEO and founder — a registry-grade identity for the entity that develops CryptPad and runs the flagship instance.
The repository README states that CryptPad is developed by a team at XWiki SAS, names its funding history — a French state research grant via BPI France from 2015 to 2019, then NLnet PET, NGI TRUST, NGI DAPSI, cryptpad.fr subscribers and Open Collective donations — and states the software is and will always be available under the GNU Affero General Public License v3 or later; it also concedes that the encryption code is loaded from the host server like any web page and that users cannot verify whether an operator logs their IP.
CryptPad's about page states that all data is encrypted in the browser so that even service administrators cannot see document content or user data, that the project does not offer free services in order to sell user data, that there are no investors positioned to profit from user data, and that development has been supported since 2016 by French and European grants (BPI France, NLnet Foundation, NGI Trust, Mozilla Open Source Support) with the goal of being fully funded by subscriptions and donations.
Privacy Guides lists CryptPad as its recommended document-collaboration platform, a category whose minimum requirements include being open source, supporting real-time collaboration and standard export formats, and describes all content on the service as end-to-end encrypted.
CryptPad's published threat model (Blueprints, Theo von Arx, 16 March 2023) states that because the server also delivers the client JavaScript, users must trust the server to provide the correct application — it is modelled as honest-but-curious, not malicious — and cites as a real precedent that a third-party CryptPad instance was forced to give law enforcement access to its data, which was encrypted; it lists end-to-end encryption of all user data and plausible deniability of accounts as design goals.
A March 2022 status post states that CryptPad was invited into a bug bounty programme coordinated by Intigriti and sponsored by the European Commission, which ran from mid-January to mid-March 2022 with independent researchers probing the code, and that the 4.13 release addressed the resulting security issues.
A June 2025 CryptPad blog post discloses two issues reported by an outside researcher (Lachlan Davidson of Carapace) against version 2024.12.0 — a DOM-based XSS vector confined to the sandbox domain and blocked by CSP, and a 2FA bypass — both fixed in 2025.3.0, with the team publishing the technical details and links to the affected code.
CryptPad's published security policy (last updated 23 June 2026) states that all fixed security issues are disclosed as CVEs on cve.org after an embargo of at least 90 days from the fixing release, reports go to a dedicated security@cryptpad.org inbox and private GitHub advisories, dependencies are scanned with npm audit and Dependabot, and code requires review by a second team member before merge; it names no monetary bug bounty.
A June 2026 CryptPad blog post states that, through the openDesk project, CryptPad's code was audited for security by Uni Systems at the request of Germany's Federal Office for Information Security (BSI), yielding CVE-2025-51846 (unbounded WebSocket frame flood, CVSS 7.5); the same vulnerability was exploited in a denial-of-service attack that took the flagship cryptpad.fr offline for under three hours on 28 January 2026, which the team post-mortemed publicly, admitting it was slow to respond and publishing a new security policy in consequence.
The administrator guide states that instances must show an absence of analytics and third-party trackers to be listed in the project's public directory, and discloses that every instance by default sends a daily opt-out telemetry message to the development team's server counting instances and versions, with a separate opt-in for aggregate usage statistics.
CryptPad's developer guide states that the only unencrypted per-user identifier sent to the server is a random public signing key, that contributions sending identifying data (username, avatar, contact list) to the server are refused, and that the server's Content-Security-Policy prohibits loading any JavaScript from an external site or CDN — all scripts must be hosted on the instance's own origin — which structurally excludes third-party analytics or ad scripts from the app.
The user guide's security page states that CryptPad's markdown-based editors (Code/Markdown, Slides, Kanban) block images and other remotely hosted content specifically to prevent potential tracking of readers.