Search inside each book
Find keywords in the full text of local TXT and EPUB files, rather than relying only on filenames, titles or metadata.
GrepTag.
Search inside your library.
Search the words inside local TXT and EPUB files, then tag books from what they actually say. GrepTag gives your collection full-text search without relying on filenames, manual metadata or a cloud index.
iPhone · iPad · Mac · Windows · Search runs on-device
At a glance
How can I find a keyword inside TXT and EPUB books?
Choose a local library folder and search the full text of its files. GrepTag shows matching books, lets you apply tags from the results, and can rerun saved AND, OR and NOT keyword profiles as your collection grows.
From finding to organisingSearch the text.
Search the text.
Keep the useful tags.
Reuse keyword profiles
Combine AND, OR and NOT terms in saved profiles. Rerun them when your collection grows, or enable automatic tagging on import.
Give plain text a cover
Match a TXT file with an image in its folder, paste a cover URL, or use the cover already inside an EPUB.
Local by design
Your library stays yours.
Search runs on-device and GrepTag does not maintain a cloud index. Its tag database is exportable as JSON. Wi-Fi sync moves files and tags over your own local network; iCloud carries only small discovery metadata if you enable it.
Read Modern Logic Tech’s privacy policyCommon questions
GrepTag FAQ
Which file types can GrepTag search?
GrepTag searches the full text of local TXT and EPUB files.
Can I save searches with more than one keyword?
Yes. Make reusable keyword profiles with AND, OR and NOT logic, then run them again as your collection changes.
Can GrepTag tag new books automatically?
Yes. You can enable automatic tagging on import so saved profiles run when new files are added.
Can I export my tags?
Yes. GrepTag keeps an exportable JSON tag database.
Does GrepTag upload my library?
No. Search runs on-device and there is no cloud index. Wi-Fi sync stays on your own network. If enabled, iCloud carries only small discovery metadata.
Which devices support GrepTag?
GrepTag is available for iPhone, iPad, Mac and Windows.