How Boolean search works
Short answer
A Boolean string joins keywords with AND, OR and NOT. Put alternatives for one requirement in brackets joined by OR, join different requirements with AND, quote multi-word phrases and exclude noise with NOT. For example: ("Software Engineer" OR Developer) AND Python NOT intern. LinkedIn, Google and Bullhorn each write exclusions and wildcards differently, so the generator writes a separate string for each.
Boolean operators on LinkedIn, Google and Bullhorn
The rules come from each platform's own documentation, listed under Sources, with one exception: Google's current help pages do not cover OR, the implied AND or brackets, so those Google entries describe how its search behaves. LinkedIn's search bar and Recruiter follow the same rules.
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| To match | Bullhorn ATS | ||
|---|---|---|---|
| Both terms | AND | a space | AND |
| Either term | OR | OR, in capitals | OR |
| Exclude | NOT | -term (no space) | AND NOT |
| Exact phrase | "quotes" | "quotes" | "quotes" |
| Grouping | ( ) only | ( ) | ( ) |
| Wildcard | Not supported | Not for word endings | develop* |
| + and - | Not supported | - excludes | Not documented |
| Location | Locations filter | Keyword | Location filter |
LinkedIn evaluates quotes first, then parentheses, then NOT, then AND, then OR. Without brackets, Python AND Django OR Flask means (Python AND Django) OR Flask, which matches every Flask profile whether or not it mentions Python. The generator brackets every OR group so the meaning never depends on precedence.
How to build a string that finds the right people
- Start with title variants. The same job is called Software Engineer, Developer and Programmer depending on the company. Missing a variant loses those people entirely. The generator suggests common alternatives for the title you type.
- Keep must-haves to two or three. Each AND removes everyone who did not write that word on their profile, including good candidates who described it differently.
- Give each must-have its alternatives. Write "AWS, GCP, Azure" on one line when any cloud will do. It becomes
(AWS OR GCP OR Azure). - Exclude the people who match for the wrong reason. Recruiters, interns and students mention the same skills. A short NOT list removes them.
- Run it, read 20 results, then tighten. If the first page is off-target, add a must-have. If it is thin, move a must-have into "At least one of", where any single match counts.
LinkedIn Recruiter and LinkedIn search
LinkedIn says operators must be typed in capitals for search to work correctly, and that + and - are not officially supported even when they seem to work. It ignores stop words such as "by", "in" and "with", and does not support wildcards.
In Recruiter and Recruiter Lite, Boolean works in the Keywords filter and in filters such as Job titles and Companies. LinkedIn warns that too many terms in one Boolean query can cause a search result issue and suggests moving terms into those filters. The Recruiter output above follows that advice: titles go in Job titles, skills and exclusions in Keywords, and place in the Locations filter.
Google X-ray search for LinkedIn profiles
site:linkedin.com/in limits Google to public LinkedIn profile pages. Google documents quotes, - for exclusions and site:, with no space between an operator and its term. OR is missing from Google's current help pages but works when written in capitals.
Google is widely reported to ignore words after the 32nd in a query. Google does not document the limit, so the generator counts words and warns past 32. X-ray only reaches profiles whose owners made them public and that Google has indexed, so it misses people that Recruiter finds.
Sources
- LinkedIn Help, Using Boolean search on LinkedIn: capital operators, quotes, parentheses, precedence, no wildcards.
- LinkedIn Help, Use Boolean to filter search results in Recruiter and Recruiter Lite: fields that accept Boolean, stop words, the too-many-terms warning.
- Google Search Help, Refine Google searches: quotes, minus and site:.
- Bullhorn, Understanding Boolean logic and new candidate list FAQ: AND, OR, AND NOT, quotes, parentheses, * wildcards and the Use Boolean toggle.
Checked on 5 November 2026. If a platform changes its rules, tell us through the contact page.
Frequently asked questions
What is a Boolean search string?
A search query that combines keywords with AND, OR and NOT. AND requires both terms, OR accepts either, NOT removes results containing a term, quotes match an exact phrase and parentheses group alternatives. Recruiters use them to find candidates in LinkedIn, Google and their ATS.
Does LinkedIn support Boolean search?
Yes, in the main search bar and in LinkedIn Recruiter and Recruiter Lite. LinkedIn's help pages say AND, OR and NOT must be typed in capitals, quotes mark exact phrases and parentheses are the only grouping symbols it recognises. In Recruiter, Boolean also works in filters such as Job titles and Companies.
Can I use wildcards like developer* on LinkedIn?
No. LinkedIn's help says it does not support wildcards, braces, brackets or angle brackets in Boolean searches. List the word forms you want as alternatives instead, for example (developer OR development). Bullhorn does support a trailing * wildcard.
What is a Google X-ray search?
A Google search restricted to one site with the site: operator, such as site:linkedin.com/in for public LinkedIn profiles. It finds people without a LinkedIn Recruiter seat, but only profiles their owners made public and Google has indexed.
How do I exclude words in Bullhorn?
Turn on Use Boolean in the candidate search and write AND NOT before the term, for example "software engineer" AND NOT intern. Bullhorn's Boolean guide documents AND NOT as its exclusion operator.
Why does my LinkedIn Boolean search return too few results?
Usually one of three things: operators typed in lowercase are read as ordinary words, every extra AND requirement cuts the pool, and LinkedIn warns that too many terms in one Boolean query can break results. Keep must-haves to two or three, move titles into the Job titles filter in Recruiter, and put alternatives inside OR groups.