What's in a Google search URL? sca_esv, ved, ei, rlz and the rest, explained
A Google results URL carries a dozen parameters beyond the search itself: sca_esv, ved, ei, oq, gs_lcrp, rlz and more. What each one is, which are documented, and which three the search actually needs.
Ken Tominaga · Updated 2026-10-01
The whole tail at a glance
Search for something, click around, and copy the address. It will look something like google.com/search?q=…&sca_esv=…&rlz=…&ei=…&ved=…&oq=…&gs_lp=…&sclient=…. Here is what is in there:
| Parameter | What it is | Documented by Google? | LinkClean |
|---|---|---|---|
| q | The search query | Yes | Keeps |
| hl, gl | Interface language and country | Yes | Keeps |
| tbm, udm, tbs | Result type and filters (news, images, the Web-only view, date ranges) | Partly | Keeps |
| sca_esv | Opaque token added since 2023 | No | Removes |
| ved | Encoded description of the link that was clicked: index, type, position | No — decoded by researchers | Removes |
| ei, sei | Session identifiers; ei begins with the time the search ran | No — decoded by researchers | Removes |
| oq | What you had typed before choosing a suggestion | No | Removes |
| gs_lp, gs_l | Search-box statistics from google.com's own box | No | Removes |
| gs_lcrp, aqs | Search-box statistics from Chrome's address bar | In Chromium's source code | Removes |
| sourceid | Which client sent the search (for example chrome) | No | Removes |
| rlz | Chrome's install-campaign tag | Yes — Chrome privacy whitepaper | Removes |
| sxsrf, iflsig | Opaque tokens | No | Removes |
| sclient, uact | Which search client and what kind of action | No | Removes |
| biw, bih | Browser window width and height, in pixels | No | Removes |
| sa, usg | Click-source code and signature on Google's redirect links; the redirect needs the signature | No | Keeps |
The three parameters a search needs
Strip a results URL down and you are left with google.com/search?q=link+cleaner. That is a complete, working search. Add tbm=nws for News or udm=14 for the Web-only view if the result type matters, and hl= if the language does. Those are the only parts that change what the reader sees.
What Google's page adds: sca_esv, ved, ei
Three parameters come from the results page itself and follow you as you refine a search or switch tabs.
- sca_esv — an opaque token that appeared in 2023. Google has never explained it.
- ved — a small encoded message describing a link on the results page: its index, its type, and its position. Decoded by outside researchers in 2013.
- ei — a session identifier whose leading bytes are a Unix timestamp: the moment the search was run.
What your browser adds: rlz, gs_lcrp, oq
Search from Chrome's address bar and the browser contributes its own parameters before Google's page adds anything.
- rlz — a promotional tag recording how Chrome was installed and in which week. The one parameter here Google documents, and it says the tag is not unique to you.
- gs_lcrp — an encoded record of how you used the address bar on the way to this search. Visible in Chromium's source as the reporting of a
SearchboxStatsmessage. - oq — the original query: the letters you had typed when you accepted a suggestion. Share a link for “link cleaner” and
oq=link+cleashows where you stopped typing.
Why this matters for a link you send
Most pages have a clean address you could share instead. A search does not — the results URL is the only handle there is, so sharing a search means sharing the address bar. With the tail attached, that address says which browser you use and when you installed it, when you ran the search, what you typed before the query you settled on, how big your window was, and which result you clicked.
None of that is the search. It is a description of the person who ran it.
How LinkClean handles it
The session keys are default-on rules scoped to Google's search domains — google.com and the main country domains. Scoping is the point: ei and oq are two-letter names that could mean anything on another site, so they are removed only where they are known to be Google's.
A results URL goes in as https://www.google.com/search?q=link+cleaner&sca_esv=5a1b2c3d&rlz=1C5CHFA_enUS1100US1100&ei=AbCdZfGhI&ved=0ahUKEwi&oq=link+clea&gs_lp=Egxnd3M&sclient=gws-wiz-serp and comes out as https://www.google.com/search?q=link+cleaner. The step-by-step version: How to share a Google search link without the tracking.
These are separate from the parameters Google Ads adds to the pages you land on after clicking an ad — gclid, gad_source and the rest — which are covered in Google's ad-click parameters.
Frequently asked
What is sca_esv in a Google URL?
An undocumented token Google Search has added to its results URLs since 2023. Its meaning has never been published. Removing it does not change the results.
Which Google search parameters can I safely delete?
Everything except q= (the query) and, if you want them, tbm= or udm= (the result type) and hl= or gl= (language and country). The rest describes your session, not the search.
Does a Google search link reveal when I searched?
It can. The ei parameter begins with a Unix timestamp set when the results page was generated. Remove ei and the link no longer carries it.
Why does my search URL have rlz but my friend's doesn't?
rlz is added by Google Chrome when you search from the address bar. A search from Safari or Firefox, or one typed into google.com's own search box, does not carry it.
Are these the same as gclid and the gad_ parameters?
No. Those are added by Google Ads to the page you land on after clicking an ad. The parameters here sit on Google's own results page URL.
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