Prompt
Can you explain the difference between semantic search and keyword search for internal company knowledge, and when each one makes sense?
Latest observation
Oct 13, 2026
OpenAI APIWeb search: off
Yes — here’s the practical difference:
Keyword search
Keyword search looks for the exact words you type, or close variants. It works well when you know the specific term used in the document.
Example:
Searching for “Q3 headcount plan” returns documents containing those words.
Good for:
- Exact names, IDs, error codes, product names
- Policies or docs where terminology is consistent
- Fast, transparent, predictable retrieval
- Cases where users know the right phrase
Limitations:
- Misses results when the document uses different wording
- Struggles with synonyms and paraphrases
- Can fail when users ask in natural language instead of using internal jargon
Semantic search
Semantic search looks for the meaning behind the query, not just the literal words. It uses embeddings / vector similarity to find documents that are conceptually related.
Example:
Searching for “how do we handle employee offboarding?” might return docs titled:
- “Termination checklist”
- “Access removal procedure”
- “Exit process for contractors”
even if those words don’t match directly.
Good for:
- Natural-language questions
- Finding docs when users don’t know the exact wording
- Surfacing related concepts and paraphrases
- Broad internal knowledge bases with inconsistent terminology
Limitations:
- Less precise for exact terms
- Can return “close enough” results that aren’t actually the right answer
- Harder to explain why a result was returned
- Often benefits from combining with other filters or keyword matching
When each makes sense
Use keyword search when:
- Users know the exact term
- Precision matters more than conceptual matching
- You need simple, explainable results
- Your corpus is structured or standardized
Examples:
- HR policy lookup by policy name
- Searching for an incident ticket number
- Finding a specific product feature or code module
Use semantic search when:
- Users ask questions in plain English
- The same concept is described in many different ways
- The knowledge base is large and unstructured
- You want a more “ask a question” experience
Examples:
- “How do I request equipment for a new hire?”
- “What’s the process for changing vendors?”
- “Where do I find the latest onboarding steps?”
Best practice: combine them
For internal company knowledge, the best system is often hybrid search:
- Keyword search for exact matches and filters
- Semantic search for meaning and recall
- Optionally rerank results using both signals
This gives you:
- Better coverage
- Better precision
- Better user experience
If you want, I can also give you:
- a simple architecture for hybrid enterprise search, or
- a decision matrix for choosing between keyword, semantic, and hybrid search.