Open-source software

Last updated September 11, 2026 · FortyNote LLC

FortyNote is built on the work of others. The libraries below are bundled with the app and run in your browser. Their licences require that we credit them and reproduce their terms, which we do here with thanks. We serve every one of them from our own servers. Two pieces of code do come from elsewhere, both only on the sign-up screen and both named below: the anti-bot check and, when you are starting a paid plan, the card fields.

PDF.js

github.com/mozilla/pdf.js · Licence text

pdf-lib

Creates and edits PDF files — rotating, merging, splitting, watermarking and page numbering. Copyright © Andrew Dillon and contributors. Licensed under the MIT Licence. Includes fflate (MIT, Arjun Barrett), pako (MIT, Vitaly Puzrin and Andrei Tuputcyn) and tslib (Apache-2.0, Microsoft Corporation).

github.com/Hopding/pdf-lib

jsPDF

github.com/parallax/jsPDF

qrcode.js

github.com/kazuhikoarase/qrcode-generator

The MIT Licence

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the “Software”), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED “AS IS”, WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

The Apache Licence, Version 2.0

Licensed under the Apache License, Version 2.0 (the “License”); you may not use these files except in compliance with the License. You may obtain a copy of the License at apache.org/licenses/LICENSE-2.0.

Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an “AS IS” BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.

What we load, and what we don’t

Once you are signed in, FortyNote loads no scripts, fonts, styles or images from third-party servers. Everything above is served from our own domain, pinned to a specific version. While you are writing, reading or searching your notes, nothing leaves your browser for anyone but us — which is why there are no third-party cookies in the app and no requests to anyone else.

The sign-up screen is the exception, and there are exactly two:

hCaptcha, on the Create-account form, to keep automated sign-ups out. It loads from js.hcaptcha.com and only while that form is on screen.
Stripe, when you arrive from one of our pricing pages to start a paid plan. The card fields on that screen are Stripe’s own, running in Stripe’s frames, loaded from js.stripe.com. We do this deliberately: a card number must never pass through our code, and the only way to guarantee that is to let Stripe collect it. It loads only on that screen, only when a plan was chosen, and never again once you are inside the app.

Neither of them can read your notes: your notes are encrypted with a key derived from your password, and nothing is decrypted on the sign-up screen. If Stripe’s script fails to load, sign-up still works — you are sent to Stripe’s own hosted page to pay instead.

One exception, for the sake of being exact: if you export a note that contains a diagram, the exported HTML file asks a public CDN for the diagram renderer when you later open that file, so it can draw the diagram outside FortyNote. It affects only exported files opened in your own browser, it carries none of your content, and nothing of the sort happens while you are using the app.

Contact

If you believe we have missed an attribution or credited something incorrectly, please tell us at legal@fortynote.com and we will put it right.