Searching your library

Search is the core feature of Theca. Type what you remember—an idea, a concept, a rough phrase—and Theca finds the relevant passages across your library, even if the book uses different words than yours.

How search works

Theca combines two methods at once: it searches by the meaning of your query and by the exact words you typed. This means that if you search for "how the brain consolidates during sleep", you will find passages about memory consolidation during sleep even if they don't contain that exact phrase.

The default mode is Hybrid and works well in most situations. If you need to locate a very specific verbatim phrase, switch to Keyword. If you want to explore a topic by meaning regardless of the exact words, use Semantic.

Searching your whole library or specific books

By default, the search covers the Whole library. To narrow results to a subset of books, switch the scope to Selected books and pick the titles in the selector that appears below. The search runs once you close the selector or click away.

How results are presented

Each result shows a passage excerpt with the relevant words highlighted, the book title, and the page where it appears. Results can be viewed in two layouts:

• List — all passages in order of relevance.
• By Book — passages grouped under each book title, useful when searching across several books at once.

Next to each result there are two buttons: Open here takes you to the passage inside the Theca reader; Open in new tab opens it without losing your position in the search view.

Every result always shows its source: book and page number. You will never see a passage without knowing where it comes from.

Page preview

When the view mode is set to Book preview, results show a thumbnail of the book page with the passage highlighted. Switch to Plain text if you prefer to see only the text without the image.

Advanced options

The Advanced options button reveals additional controls to adjust the number of results and the balance between semantic and keyword search. To return to the original settings, click Reset to defaults.

Frequently asked questions

Why do results appear even when I don't use the exact words from the book? Theca also searches by meaning. If the concept is similar, the passage may appear even if the words are different.

Can I search within a single book? Yes. From the detail card of any book in your library there is a direct shortcut to search within that book. You can also use Selected books on the search screen.

What happens if there are no results? Try different keywords or switch the search mode. If a book shows Not processed status, it needs to be processed first before its passages become searchable.

Is my search history saved? Yes. Theca remembers your recent searches so you can repeat them with a click. See the search history article.

Next step

• AI overview — how Theca generates a summary of your results from your own books.
• Search history — how to reuse your recent queries.
• Summaries — generate full summaries of your books with traceable citations.