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temp.cool
Comparison

temp.cool vs Onetime Secret

1 min read · Updated

Short answer

Both send a secret that can be read once. temp.cool encrypts in your browser so its server never sees the text, and stores everything in the EU; Onetime Secret is open source, lets you pick an EU or US data region, and offers custom domains on paid plans.

  1. Where encryption happens

    temp.cool encrypts in your browser and only ever receives scrambled text. Check Onetime Secret's own docs for how and where it encrypts.

  2. Where data lives

    temp.cool stores messages in the EU only. Onetime Secret lets you choose between data regions, including the EU.

  3. Open source

    Onetime Secret's code is public, so you can run your own copy. temp.cool is a hosted service.

At a glance

temp.cool Onetime Secret
Free to use, no account Yes Yes
Encrypted in your browser before sending Yes See their docs
Data location EU only Choice of regions, incl. EU
Password on the link Yes, destroyed after 4 wrong tries Yes
Views per link 1 to 10 1
Link preview protection Yes, needs a tap See their docs
Open source, self-hostable No Yes
Your own domain Paid plans Paid plans
Languages English, Dutch Several

We checked Onetime Secret’s public documentation in October 2026. Features change, so check their site for the latest.

Pick temp.cool if

  • You want the server to never see the secret, not even for a moment.
  • You need data to stay in the EU without choosing a region.
  • People open your links in WhatsApp, Slack or Teams, where previews can burn a one-time link.
  • You want to share a secret with a small group, up to 10 views.

Pick Onetime Secret if

  • You want to run the software yourself on your own servers.
  • You need a data region outside the EU.

How temp.cool’s encryption works

Your browser encrypts with AES-256-GCM. The key travels only in the part of the link after the #, which browsers never send to a server. Read the full design on the security page.

Got a secret to send?

Free, no account. Read once, then poof.

Write a secret