Is it safe to paste work data here?
The technical answer, and what to check with your own organisation.
Technically, yes — that is the reason the tools run locally. Whether your organisation's policy allows it is a separate question that only they can answer.
What actually happens
Your input is processed by JavaScript running in your browser, on your device. There is no server that could receive it, no request is made, and nothing is logged. Loading the page fetches static files from a CDN; after that, nothing.
How to demonstrate it
Open the network panel, clear it, use a tool, and observe that no request appears. Or load a tool page, disconnect from the network, and watch it keep working. Both are more convincing than a policy document.
For a security review
The security page lists the specific measures — no eval anywhere, sanitised and sandboxed previews, no external entity resolution in the XML parser, CSPRNG for all generated values. The privacy centre shows the complete list of what is stored locally.
If policy forbids external sites entirely
The whole site is static files. It can be built and served from your own infrastructure with no changes and no backend.