EPUB Find & Replace

EPUB Find & Replace lets you open an EPUB book, replace a word or phrase throughout it, and download the edited copy — all directly in your browser. Everything runs locally. The extension requests no permissions, declares no host permissions, includes no content scripts and no background service worker, and makes no network requests. Your file never leaves your machine. Features • Drag-and-drop or click to open an .epub file. • Find any text, or use a JavaScript regular expression with $1, $2, … back-references in the replacement. • Case-sensitive or case-insensitive matching. • Downloads a new file named <original>-edited.epub. • Report of results: total replacements plus a per-file breakdown so you can see exactly what changed. • Preserves images, fonts, and other binary resources byte-for-byte. • Preserves the required "mimetype" first-entry, stored EPUB structure so readers accept the output. Privacy by design Because the extension has an empty permissions list, an empty host_permissions list, no background page, and no network access, there is nothing for it to send anywhere. Everything happens in the popup, in memory, on your machine. Requirements • Chrome 103 or newer (uses the built-in CompressionStream / DecompressionStream "deflate-raw" format). Known limitation A phrase split across HTML formatting tags in the source markup (e.g. "<em>Hello</em> world") may not match, because replacement operates on the underlying markup, not on rendered text.