search query length limits?

This is an incomplete doc about search query length limits.

From Perplexity AI's marketing email today:

Longer Input Limits

Did you know Perplexity can write code, essays, and summarize articles? To help, input limits have been increased to 2000 tokens (roughly 1500 words).

Entirely apart from the generative results, I find the changes in query length constraint in using generative search tools very fascinating.

Are there any older general-purpose web search tools that take long text-based queries (more than 32-words) and reduce their length through an internal or assisted reformulation prior to retrieving results from the index?

That could exist outside of the other generative aspects.

Search Tools and Query Length Limits

Search ToolQuery Length LimitComments
Bing2000 charactersfour more characters allowed in the SERP
Bing Web Search API1,500 characters (suggested)[Web Search API v7 reference](https://learn.microsoft.com/en-us/bing/search-apis/bing-web-search/reference/endpoints):
The maximum URL length is 2,048 characters. To ensure that your URL length does not exceed the limit, the maximum length of your query parameters should be less than 1,500 characters. If the URL exceeds 2,048 characters, the server returns 404 Not found."
danielsgriffin.comunlimited or 524288 characters[The default limit of the HTML input form for text is unlimited.](https://html.spec.whatwg.org/multipage/form-control-infrastructure.html#maximum-allowed-value-length) ([See also this page on Stack Overflow for why it may sometimes be 524288 characters.](https://stackoverflow.com/questions/26469152/why-is-the-default-max-length-for-an-input-524288))
DuckDuckGo496 characters ([?](#duckduckgo-call-me-ishmael))=2^4×31
Google32 wordsafter stopwords removed
Perplexity AI2000 tokens (roughly 1500 words)
You.com "All" Search40 wordsYou can select to include the fuller query (which sometimes prepends a `+`?):
"Limited query to 40 words and showing results for: [ . . . ]
Show instead for: [ . . . ]

Selected examples

Google [ Call me Ishmael. Some years ago—never mind how long precisely—having little or no money in my purse, and nothing particular to interest me on shore, I thought I would sail about a little and see the watery part of the world. It is a way I have of driving off the spleen and regulating the circulation. ]
A Google[Call me Ishmael. Some years ago—never mind how long precisely—having little or no money in my purse, and nothing particular to interest me on shore, I thought I would sail about a little and see the watery part of the world. It is a way I have of driving off the spleen and regulating the circulation.] search. Screenshot taken with [GoFullPage](https://gofullpage.com/) (distortions possible) at: 2023-07-06 10:34:44

Bing [ Call me Ishmael. [ . . . ] landsmen; ]
A Bing[Call me Ishmael. [ . . . ] landsmen;] search. Screenshot taken with [GoFullPage](https://gofullpage.com/) (distortions possible) at: 2023-07-06 11:15:22
Bing let me add four more characters (" of ") from the SERP itself.

DuckDuckGo [ Call me Ishmael. [ . . . ] bringing up the ]
A DuckDuckGo[Call me Ishmael. [ . . . ] bringing up the] search. Screenshot taken with [GoFullPage](https://gofullpage.com/) (distortions possible) at: 2023-07-06 11:34:58