When I search for something on Google and then go to Videos tab, I get a URL like


(url for searching tester in Incognito mode without active extensions)

What is sca_esv? ClearURLs extension does not block it.

From what I can tell, the number stays the same cross-search—even when I am in incognito mode.

  • Mine is 569877865
  • Removing the query parameter does not seem to affect the results of search

Useful Information

  • Not UNIX time. The time is constant as well as being Friday, January 22, 1988
  • Does not appear to be tied to IP. When I change location in VPN, I still get 569877865
  • When Googling "sca_esv" the first result is a HN article with sca esv=560664892 perhaps there is some A/B testing Google is doing with sca_esvtargetting programmers?
  • Googling on my iPhone, I get sca_esv=569877865
  • Mullvad browser (without VPN, signed out of Google) I also get sca_esv=569877865
  • Mullvad browser (with VPN, signed out of Google) I get 569877865
  • Tor Browser fresh install (signed out of Google) I get sca_esv=569877865 what???? how does it know... circuit is even in a different country (Netherlands while I am in Chicago)
  • I had my friend search hi string and they got a different sca_esv. When they search tester they got the same sca_esv as me when I search tester (569877865). It looks like it is related to the query possibly. It is sticky: searching tester then hi, hi will have the same sca_esv as tester (569877865). It appears to be sticky even across many different browsing sessions on Firefox for my friend.
  • tester sca_esv has priority over hi sca_esv. Once my friend searched for tester, they were stuck with it and could not get back to hi sca_esv

Tor Browser circuit

Is it some type of tracking ID perhaps?

Brainstorming sca_esv meaning

Asking ChatGPT to brainstorm what sca and esv could stand for in the context of a Google search:

The sca_esv parameter is a piece of data in the URL that's likely internal to Google's system for tracking, sorting, or customizing search results. URL parameters like these are often used for various purposes including analytics, session identification, and to tweak the behavior of the search. As for brainstorming what sca_esv might stand for, here are some speculative guesses:

  1. Search Context Algorithm - Elapsed Seconds Value: This could indicate that the search query has some kind of time-based context.
  2. Sorted Content Algorithm - Effective Sort Value: This might represent some value that helps in sorting the content in a particular way that Google's algorithms find effective.
  3. Session Customization Attribute - Event Specific Value: Perhaps this is a value that gets updated based on certain events or conditions met during your session.
  4. Systematic Categorization Algorithm - Engine Specific Variable: This could be a parameter specifically meant for Google's video search engine, categorizing the search in a systematic way.
  5. Search Customization And - Epoch Start Value: This could represent the start time for the search session in a specific time format, such as Mac Absolute Time as you mentioned.
  6. Server Client Agreement - Expiry Stamp Value: This might be a value indicating some sort of expiration or a time-sensitive attribute that gets reset.

2 Answers 2



According to unfurl it is timestamp.


Extract and Visualize Data from URLs

GitHub readme file excerpts:

Extract and Visualize Data from URLs using Unfurl

Unfurl takes a URL and expands ("unfurls") it into a directed graph.

It does this by breaking up a URL into components, extracting as much information as it can from each piece, and presenting it all visually.

Unfurl has parsers for URLs, search engines, chat applications, social media sites, and more. It also has more generic parsers (timestamps, UUIDs, etc) helpful for exploring new URLs or reverse engineering. It’s also easy to build new parsers, since Unfurl is open source (Python 3) and has an extensible plugin system.

  • Ok, it's a timestamp, but a timestamp of what? The OP has made a guess, "I think it is some type of tracker ID that unifies all my devices. Is this correct?". Your answer will be more complete if you mention something about that guess :) Commented Oct 2, 2023 at 6:01
  • According to unfurl, it is Mac Absolute Time / Cocoa—the number of seconds since 01.01. 2001 00:00:00 UTC. Odd it is 2019-01-22, though. I agree, would be interesting to know what it is a timestamp of. Commented Oct 2, 2023 at 16:26
  • @Rubén I edited the OP with better guesses from ChatGPT given it is a timestamp. Elapsed seconds value for esv seems promising. Commented Oct 2, 2023 at 16:32
  • Also interesting I cannot find sca or esv in unfurl source. Perhaps the web version uses different source? Or perhaps (I think this is more likely) unfurl has no idea and is just guessing. Commented Oct 2, 2023 at 16:36
  • Please, despite what some people are claiming, I'm sorry to say that it does not look like a good fit for web applications. Please consider creating a chatroom so you can continue collaborating on this topic in the meantime that you find a site where a question like this is a good fit: discovering the meaning / usage of obscure query string parameters of major web applications like Google (Google Search) with or not privacy / tracking concerns. Commented Oct 2, 2023 at 16:46

Google hasn't documented all URL parameters on the help centers of Google (websearch), Google Search Console Tools, and Google Search Center Central

Most documented parameters are intended to interact with web browser settings that end-users and professionals could customize. A group of these professionals used to be referred to as webmasters, another group is software developers. There is a lot user created content about officially and not documented parameters.

Some parameters are not documented on the help center, and Googlers and the community have documented Google Developers articles, most of them are related to user-entered input parameters or parameters that might be used when crafting URLs, i.e, to integrate Google into a website search feature.

On the Stack Exchange network, it might be possible to find questions about them here, on Webmasters Stack Exchange, Stack Overflow, Super Users and probably on others sites too.

Asking a generative AI tool like ChatGPT might be helpful to get insights about possibilities, but be careful about making conclusions without cross-referencing the responses, as it's well known that this tool could hallucinate.

Tools like unfurl, mentioned in the previous answer, help to analyze URLs. You should look at their documentation to learn about the features and limitations. It is worth mentioning that a few days ago, on September 27, 2023, there was a new release. This tool has an online front-end (web application): https://dfir.blog/unfurl/.



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