Keyword Extractor

Extract the most important keywords and phrases from any text. Uses TF-IDF scoring to identify terms that best represent your content.

How It Works

This tool uses a variant of TF-IDF (Term Frequency–Inverse Document Frequency) adapted for single-document analysis. The text is split into sentences which act as pseudo-documents, allowing the algorithm to identify terms that are frequent overall but concentrated in specific parts of the text — a strong signal of topical importance.

The scoring works in three steps:

1. Term Frequency (TF) — How often a word appears in the entire text, normalized by total word count.
2. Inverse Document Frequency (IDF) — Words that appear in every sentence are penalized; words concentrated in fewer sentences score higher.
3. N-gram extraction — Beyond single words, the tool identifies meaningful 2-word and 3-word phrases by looking for frequently co-occurring non-stop-word sequences.

Stop words (common words like "the", "and", "is") are filtered out automatically. The remaining terms are ranked by their TF-IDF score and presented with relative importance bars.