Why we do it this way
If you paste a key in an email or chat, it sits there forever: in your inbox, our inbox, backups, and anyone who gets into those accounts later.
OneTimeSecret gives you a link that works once. After we open it, the key is deleted from their server. If anyone opens the link later, they see nothing.
Free, no account needed. Data is stored in the European Union if you use the link below.
Step by step
Copy the key from the tool
Follow the page for that tool in this guide. Keep the key on your clipboard.
Open OneTimeSecret (EU)
Go to eu.onetimesecret.com. This stores the secret in the EU.
Paste the key, with a label
In the big text box, write what it is on the first line, then paste the key. For example:
Smartlead API key a1b2c3d4-e5f6-...If the tool gave you two codes (like Client ID and Client Secret), put both in the same box, each on its own line with its name.
Set the expiry to 7 days
Under Expiration Time, choose 7 days. This is the maximum without an account.
(Optional) Add a passphrase
For payment or Google keys, type a short Passphrase. Send it to us by a different channel (for example by phone or WhatsApp if the link goes by email).
Click Create Link
Click Create Link. You see a page with your link and a copy button.
Copy the link and send it to us
Copy the link and send it to us by email or Slack. The link is safe to send: it doesn't contain the key itself.
Careful
Do not click the link yourself. It works only once. If you open it, the key is gone and we can't see it. If that happens, just make a new link.
Good to know
Can I put several keys in one link?
Yes. One link can hold up to 10,000 characters. Put each key on its own line with the tool name above it.
How do I know you received it?
Keep the receipt page open (or bookmark it). It shows when the secret was viewed.
I sent the link to the wrong person
On the receipt page click Burn this secret, then confirm. The link stops working. If it was already viewed, delete the key in the tool and create a new one.
The link expired before you opened it
Nothing leaked. Create a new link with the same key and send it again.
Last checked: 22 Oct 2026 against onetimesecret.com and its open-source code.