Messaging apps do not add tracking parameters to your links. They do something arguably more consequential, which is that they are where other platforms' tracking parameters travel furthest.
This post is the one place in the series where the platform is not the culprit. It is the vector.
The forwarding problem
Almost every parameter covered in this series identifies the person who first copied the link. Instagram's share identifier. Mailchimp's recipient ID. TikTok's browser identifier. Facebook's click token.
None of those are removed when a link is forwarded. A URL pasted into a family group chat, forwarded to another chat, screenshotted, retyped, and sent to a fifth group carries the same identifiers it started with. The person who generated them may have left the conversation years earlier.
Scroll back through any long-running group chat and look at the links. Most are carrying somebody's identifiers, and in a lot of cases nobody in the current conversation is the person they belong to.
Where this gets uncomfortable
Mailchimp is the clearest case. A newsletter link contains mc_eid, which resolves to an individual subscriber on the sender's list. Forward that into a group and everyone who clicks registers as you in the sender's reporting. I have written about it properly in Mailchimp's tracking parameters, and it is the parameter I would most encourage people to strip before sharing.
The others are milder but the mechanism is identical. An Instagram link with an igshid on it, described in how to clean Instagram links, is a share identifier belonging to whoever copied it first.
Link previews
Separate issue, worth knowing about because people ask.
When you paste a link into a chat, a preview appears with a title and image. Something has to fetch the page to build that preview. Depending on the app, this may be done by your own device or by the platform's servers, and the two behave quite differently from a privacy point of view.
Telegram generates previews server-side, which is why a preview can appear for a link even if nobody has tapped it. WhatsApp handles preview generation on the sending device.
The practical implication is small but real: pasting a URL into a chat can cause it to be fetched, even if nobody clicks. If you are sharing something genuinely sensitive, such as a one-time access link or an unsubscribe URL, that is worth knowing. Most apps let you remove the preview before sending.
What is actually worth doing
I want to be proportionate here, because it would be easy to write this post in a way that makes ordinary messaging sound alarming, and it is not.
Clean links before you forward them. That is the entire recommendation. Not because any individual link matters much, but because it is the one point in the chain where a small action stops something propagating.
Never forward an unsubscribe link or a one-time login link. Those contain identifiers by necessity, and unlike tracking parameters they actually do something when clicked.
Beyond that, I would not lose sleep over it.
wa.me and t.me links
Both platforms have their own link formats, and neither carries tracking in the sense used elsewhere in this series.
wa.me/1234567890 opens a WhatsApp chat with a number. Adding ?text= prefills a message, which is functional rather than tracking, though it does mean the URL contains whatever message was prefilled.
t.me/channelname opens a Telegram channel. t.me/channel/123 opens a specific message.
Neither needs cleaning. The thing worth noticing is that a wa.me link contains a phone number in plain text, so sharing one publicly shares that number.
How to clean before sending
Paste the link into the link cleaner online, copy the result, then send that.
On mobile this is more friction than it sounds, and I will not pretend otherwise. Realistically most people will do it for links they are sending to a group or posting publicly, and skip it for one-to-one messages. That is a reasonable place to draw the line.
Related reading
What is fbclid for the parameter you will encounter most often in forwarded links.
The URL tracking parameter glossary for identifying anything unfamiliar.
Frequently asked questions
Does WhatsApp add tracking to my links?
No. WhatsApp does not append parameters. The tracking in a forwarded link came from wherever it was originally copied.
Can WhatsApp read the links I send?
Message content is end-to-end encrypted. Preview generation on the sending device happens before encryption, which is a different question from the platform reading your messages.
Why does a preview appear before anyone clicks?
Because something fetched the page to build the preview. On Telegram this happens on the platform's servers.
Should I clean every link I send?
Worth doing for group chats and anything public. For one-to-one messages it matters much less.
What about links people send me?
Clean them before you forward them onward. There is nothing to fix about receiving one.