Reading Progress & Re-read History
Codex tracks two separate things about what you read, and it helps to know which is which:
| Holds | Changed by | |
|---|---|---|
| Reading progress | where you are right now in a book | reading, marking read/unread |
| Read history | every time you have finished a book | finishing a book, or clearing history |
Progress is current state. History is a permanent log. Marking a book unread resets the first and leaves the second alone, which is what lets you re-read a favourite series without pretending you never read it.
Reading progress
Your position is saved as you read, and syncs across devices and clients:
- The Continue button on a book, and the Keep Reading and On Deck rows on the home page, all come from this.
- A book counts as read when you reach the last page, or when you use Mark as Read.
- Mark as Unread discards your position entirely, putting the book back to never-opened.
Progress arriving from a Komga-compatible app, a KOReader device or an external tracker sync is treated exactly the same as progress from the built-in reader.
Read history
Every time you finish a book, Codex records the completion: when that pass started and when it finished. Book and series pages show the result:
You've finished this book 2 times, last on 5 Mar 2025
Expand the section to see each read-through with its dates. The section is hidden entirely on anything you have never finished, so it only appears once there is something to show.
What counts as finishing again
A new entry is recorded when you finish a book after marking it unread. Marking unread is the signal that a new read-through has started.
That distinction matters because of what it excludes:
- Tapping back a page and forward again does not count twice. Turning back from the last page technically un-finishes the book, and turning forward finishes it again, but it is obviously the same read-through and Codex treats it as one.
- Re-sending "completed" does not count twice. Some clients re-assert the read state on every sync; that never inflates the count.
- Re-reading without marking unread is not counted. If you scroll back to page 1 while your progress is still there, Codex cannot tell that apart from browsing backwards through a long volume, so it stays one read-through. Mark the book unread first if you want the re-read recorded.
Series history
A series counts as read once every book in it has been read. So the series count is the lowest count across its volumes, not the highest:
- Read all six volumes: the series has been read once.
- Re-read volume 1 only: still once, because volumes 2-6 have only had one pass.
- Re-read all six: twice.
Each series entry spans from the earliest volume start of that pass to the last volume finish, so it describes when you were reading the series as a whole.
Adding a new volume to a series you had finished drops the series count to zero, because the series is no longer fully read. That is intended, and the earlier full-series completions stay listed on the page so the history does not appear to have vanished.
Clearing history
History can be cleared at three scopes. None of them touch your reading progress: books stay read or unread exactly as they are.
| Scope | Where | Clears |
|---|---|---|
| One book | the history section on a book page | that book's completions |
| One series | the history section on a series page | every book in that series |
| Everything | Settings → Profile → Account → Reading History | your whole library |
Each asks for confirmation first. Clearing is per-user: it never affects anyone else's history, and no user can see or clear another's.
What is not recorded
- Abandoned reads leave no trace. Marking a book unread at page 50 without finishing records nothing. A completion log should not contain "gave up at page 50".
- Nothing appears on library grid cards. Re-read counts show on book and series detail pages only, so browsing a library does not have to compute them for every card.
- Read lists have no completion count. History is tracked for books, and rolled up to series.
For existing libraries
Books you had already finished before this feature existed are counted: the first upgrade records one completion for every book currently marked read, dated from its completion time where that was stored and from its last-updated time otherwise. You do not need to re-read anything to get a starting count.