# One-time link vs email, WhatsApp and Slack

> Email and chat are fine for the link but not for the password itself, because they keep a copy for years on every device and backup. A one-time link holds the secret only until it is read, so a later breach finds nothing.

1. **Email keeps everything** Sent items, the recipient's inbox, server backups and every synced phone hold a copy. Years later, one hacked account leaks it.
2. **Chat is searchable** Slack, Teams and WhatsApp history is searchable by anyone in the chat, now and later, including new members and admins.
3. **A one-time link forgets** The secret is gone after reading. What stays in the chat is a dead link.

## Side by side

| | Email | WhatsApp | Slack or Teams | temp.cool link |
|---|---|---|---|---|
| Copy kept after reading | Yes, for years | Yes, on both phones and backups | Yes, searchable by the workspace | No |
| Who else can read it later | Anyone with mailbox access | Anyone with the phone or backup | Workspace admins, new channel members | Nobody |
| You know if it was read | No | Blue ticks only | No | Yes, on your manage link |
| Can you take it back | No | Only within a time limit | Sometimes | Yes, shred it any time |

## When plain email or chat is fine

For things that are not secret, or that stop working within minutes, like a one-time sign-in code that expires right away. For anything that still works tomorrow, such as a password, an API key, a door code or bank login details, use a one-time link.

## Combine them for the best of both

Send the temp.cool link in your normal email or chat. If you want extra safety, put a password on the link and say it on the phone. Someone who later reads the chat finds a link that no longer opens.

## Read next

- [How to send a password securely](/guides/send-a-password-securely/)
- [Why a link preview can't burn a temp.cool message](/glossary/#link-preview)