What is URL tracking?
Tracking parameters and unique tokens in URLs can reveal where a link came from and connect activity across contexts.
A URL is not just a string that indicates the location of a web page.
Inside a URL, there may be information that indicates not only which page to open, but which advertisement the visitor came from, which social media post was clicked, or which user the link was issued for.
Even if no name or email address is written, parameters left in a URL can become clues about the traffic source, search terms, campaign, click ID, referrer, or session information.
When thinking about anonymity, it is dangerous to check only the text and images and then paste the URL you are sharing as-is.
This article organizes what URL tracking is, which parts of a URL to check, and how to judge before sharing.
What is URL tracking?
URL tracking is a mechanism that uses information attached to a URL to measure traffic sources and user behavior.
For example, advertisements, email newsletters, social media posts, affiliate links, and campaign pages may add extra information to the end of the URL.
This additional information is often placed after ? in the URL.
Example:
https://example.com/article?utm_source=newsletter&utm_campaign=spring
The part after ? is called the query string. The query string may contain search conditions, page numbers, product IDs, click IDs, advertising IDs, referrer IDs, and similar values.
For website operators, URL tracking is used for access analytics and measuring advertising effectiveness.
However, from the perspective of anonymity, it may become a clue about the person who shared the URL or the route by which it was clicked.
Which part of the URL to look at
When checking a URL, it is important not to treat the whole thing as one block.
A URL contains parts with different meanings.
| Part | Example | What to check for anonymity |
|---|---|---|
| Domain | sample.test | Shows which site will be connected to |
| Path | /article/network | Shows which page or function will open |
| Query string | ?id=123&utm_source=sns | May contain search terms, identifiers, or tracking information |
| Parameter name | utm_source, ref, gclid | Clue for guessing what kind of information it is |
| Parameter value | newsletter, abc123 | May indicate traffic source, individual ID, or campaign |
| Fragment | #section | Often not sent to the server in ordinary HTTP requests |
Pay special attention to the query string.
Not every query string is dangerous. Search result pages and product pages may require values to display the page correctly.
On the other hand, tracking parameters that are unnecessary for sharing may be attached.
The important thing is to separate "will the page open without this value?" from "is this value for identifying someone?"
Common tracking parameters
Values often seen in URL tracking have certain patterns.
| Type | Examples | Meaning |
|---|---|---|
| UTM | utm_source, utm_medium, utm_campaign | Measures traffic source, medium, and campaign |
| Ad click ID | gclid, fbclid, msclkid | Identifies ad or social media clicks |
| Referrer | ref, referrer, source | Shows where someone came from |
| Affiliate | affiliate, aff, partner | Shows introducer or partner source |
| Sharing ID | share, invite, campaign_id | May show sharing links or invitation routes |
| Session-like value | session, sid, token | May be close to individual state or authentication |
Some values, such as UTM and click IDs, are clearly for tracking.
On the other hand, some names such as id or token cannot be judged from the name alone. An id may be an article ID, or it may be an identifier issued for each user.
It is not good to treat unknown values as "probably safe."
Failures that happen when sharing URLs
Failures involving URL tracking do not necessarily require technically difficult attacks.
Many happen simply by pasting a copied URL as-is.
| Failure | What happens |
|---|---|
| Sharing an ad URL as-is | Ad click ID or campaign information remains |
| Pasting a link from an email as-is | Identifying information for email delivery may remain |
| Sharing a search result URL | Search terms or search conditions may remain in the URL |
| Sharing a URL after login | Session or individual screen information may be mixed in |
| Sharing a shortened URL without expanding it | The destination and tracking cannot be checked |
For example, suppose someone introduces an article from an anonymous account.
They do not include personal information in the post text. However, if the pasted URL still contains an email delivery ID or ad click ID, it becomes material showing which route they obtained the link from.
That alone does not necessarily reveal a real name.
However, when combined with posting time, account, cookies, login state, and access logs, it strengthens the impression of the same person.
In anonymity, it is important not to treat such small clues lightly.
Values that may be removed and values that should not be removed
URL parameters should not all be removed blindly.
Some values are necessary for the page to open correctly.
| Type | Handling | Reason |
|---|---|---|
| utm_source and similar | Often removable | Often used for analytics and unnecessary for page display |
| gclid, fbclid, and similar | Often removable | Often used to measure ad or social media clicks |
| ref, affiliate, and similar | Check the content | May relate to referrer information or revenue measurement |
| page, q, id, and similar | Check carefully | May be necessary for page display or search conditions |
| token, sid, session, and similar | Prefer not sharing | May be close to individual state or authentication |
The basic judgment is simple.
If the same page opens after removing it, it may be unnecessary for sharing.
If removing it leads to a different page, changes search results, or loses necessary information, the value is related to the page content.
However, URLs with values such as token or session are not suitable for public sharing in the first place.
Rather than trying to clean that URL, it is safer to look for an official sharing link separately.
Check procedure before sharing
Before sharing a URL, check in the following order.
| Order | What to check | Reason |
|---|---|---|
| 1 | Check the entire URL | See whether unnecessary information exists after ? |
| 2 | Look for tracking-like parameters | Check utm, gclid, fbclid, ref, and similar values |
| 3 | Classify unknown values | Separate values needed for display from identifier-like values |
| 4 | Reopen the URL after removal | Confirm whether the same content appears |
| 5 | Expand shortened URLs | Check the final destination and intermediaries |
If possible, check while not logged in or in a separate browser.
If you check in your usual browser, cookies and login state may cause you to share a URL that "opens for you, but does not open for others."
For anonymous use, simply checking once in a separate environment before sharing can reduce failures.
URL alone does not determine anonymity
Even if you clean a URL, that alone does not make you anonymous.
A URL is one clue.
The same post also involves text, images, posting time, account, communication route, login state, and past posts.
For example, even if you remove tracking parameters from a URL, if you post while logged in to a real-name account, anonymity weakens.
Conversely, even if you use VPN or Tor, if the URL you share still contains an individual ID, correlation can happen somewhere separate from network countermeasures.
URL checking is one process within anonymity as a whole.
Summary
URL tracking is a mechanism that uses parameters contained in a URL to measure traffic sources and behavior.
UTM, click IDs, referral codes, shortened URLs, and redirects can become clues about the sharing source or traffic route.
When thinking about anonymity, check not only text and images, but also the URL you share.
The important thing is to separate values that may be removed from values that should not be removed. Tracking parameters can often be removed, while values such as search terms and page IDs may be necessary for display.
If an unknown value remains, do not treat it as safe. Delay sharing, look for another official link, or check in a separate environment.
A URL looks like a small string.
But in anonymity, that small string can show the route of an action.