Link previews are generated by the app fetching your URL and reading its tags. Sometimes you want to stop that: the preview is ugly, it takes up half the screen, the link is private, or it is a one-time link you do not want a bot to open. This post gives the switch for each app, from the vendors' help pages where they exist, checked on 19 October 2026.
Slack
For one message. On desktop, move the cursor over the preview and click the x on the left of the link. On mobile, press and hold the link in the message and tap Remove Link Preview.[1]
For every link you share. Click your profile picture → Preferences → Messages & media. Under Inline media & links, untick Show images and files from linked websites and Show text previews of linked websites. Slack notes that some third-party app previews stay on regardless; workspace owners can restrict those separately.[1]
Note that these preferences change what you see. Other people in the channel still get a preview of links you post unless you remove it from the message itself.
Discord
Discord has no setting that stops embeds for links you send. The method everyone uses is to wrap the URL in angle brackets:
<https://example.com/page>
Discord posts the link without the embed card. A backslash before the URL also suppresses the embed, but it makes the link unclickable, so the brackets are the better option. Your own Link preview toggle (User Settings → Text & Images) only controls whether you see embeds that other people post.[2]
Discord caches embeds per server; editing a message is the way to make it re-fetch. To see what the embed will look like before you post, use the Discord link preview checker.
iMessage
Messages has no setting for previews inside a conversation. What you can do is send the link as plain text: paste the URL into the message field, tap the preview card that appears, and choose Convert to Text Link. The message then carries a clickable URL with no card.[3]
Two things people try that do not work: the Show Previews option under Settings → Notifications → Messages, which only affects the lock screen, and putting full stops around the link, which in testing by others changed nothing. The iMessage link preview checker shows what the card will contain if you leave it on.
Outlook
Outlook on the web and the new Outlook app show a preview card for links you paste while composing. You can remove the card from a single message by clicking its close control before sending, and in Outlook on the web the composing preference lives under Settings → Mail → Compose and reply (look for the link preview option). Classic Outlook for Windows does not generate link preview cards. Menu names in Outlook change between versions; if the option is not where this describes, search Settings for "preview".
Why this matters for one-time links
A preview is a fetch. When you paste a link into Slack, Slack's server requests it to build the card. If the link is a one-time secret on a service that reveals the secret on a plain fetch, that preview can consume it before the person you sent it to opens it, and they see a "burned" page.
Two ways to avoid that. Turn the preview off with the steps above when you send a secret link. Or use a service built for it: LinkPilot's one-time secret link generator serves a preview fetch only the page shell, and the secret is fetched, and the view counted, when a browser runs the page. Link scanners and one-time secrets explains why that distinction matters for corporate email scanners too.
To see what any link's preview would show, across Slack, Discord, iMessage and five other apps at once, use the link preview checker.
References
[1] Slack Help Center. Share links and set preview preferences. https://slack.com/help/articles/204399343-Share-links-and-set-preview-preferences. Checked 19 October 2026.
[2] Discord Support community. Change if a link should have a preview before sending it. https://support.discord.com/hc/en-us/community/posts/360050458131. Checked 19 October 2026.
[3] iPhone Life. Turn off link thumbnails in the Messages app on iPhone. https://www.iphonelife.com/content/turn-link-previews. Checked 19 October 2026.