Kobo Rebuilds Bookmark and Reading Progress Sync 2026

Published September 12, 2026

If you have ever finished three chapters on your phone during a commute, opened your Kobo e-reader that evening, and found yourself back at the cover, you already know the problem Rakuten Kobo announced a fix for this week. On September 11, 2026, Kobo CEO Michael Tamblyn took to Bluesky to say the company had torn down and rebuilt its syncing system for bookmarks and reading progress — the plumbing that keeps your position in a book consistent across an e-reader, a phone app, and a tablet.

The admission is unusually blunt for a hardware executive, which is what makes it worth paying attention to. As reported by Good e-Reader on September 11, 2026, Tamblyn wrote: "We know some of you have been driven slowly crazy by the way your reading progress on the Kobo app doesn't always correctly sync with your e-reader or your e-reader to your app. Annoying. Bad experience. No one liked it. So we rebuilt the entire bookmarking and progress syncing system from the ground up."

For anyone who reads across more than one device, this is a bigger deal than a firmware changelog entry usually is. Progress sync is the invisible feature that makes a multi-device reading habit work at all. When it drifts, readers quietly start trusting one device and ignoring the others — and a sideloaded EPUB library becomes harder to justify.

What Actually Changed, In Plain Terms

Kobo's syncing architecture was built for an earlier version of the company. As Tamblyn framed it in the same post, the company grew from "buy a book on your e-reader and read it" into a portfolio of devices released nearly every year, plus a suite of mobile apps and a cloud reader. The old system, in his words, "was bursting at the seams," and new books and reading progress stopped behaving predictably.

The important caveat is the one Tamblyn volunteered up front, and it is worth repeating because it dominates the comments on every story about this issue: the bug only affected people who read on two or more devices. "First off, this only matters if you are an e-reader and an app user. Or a multi-ereader user," he wrote. "If you aren't trying to keep two devices in sync, this hasn't been a problem for you."

That framing matters for how you evaluate the announcement. Single-device readers will notice nothing, which is why the problem never showed up as a headline complaint on mainstream review sites. But the population of readers who split time between an e-reader and a phone screen is exactly the population Kobo and its competitors are fighting for, and it is exactly the population that has been loudest in Kobo's community channels.

The One-Time Fix: Two Steps Per Device

The good news is that the repair is not a gradual rollout or a wait-for-your-firmware situation. It is a manual reseed you run once, and the instructions differ slightly depending on whether you are fixing an e-reader or a mobile app.

1. On a Kobo e-reader: go to Settings → Device Information → Repair Your Kobo Account, and run the repair.
2. In the Kobo mobile app (iOS or Android): sign out of your account and then sign back in.
3. Repeat on every device where you are signed in — the e-reader, the phone, the tablet, and any secondary e-reader.

That last step is the one people skip, and it is the one that determines whether the fix sticks. Tamblyn was explicit about it: "You have to do this on all devices you're signed in to, but you only have to do it once; after that, everything will stay synced from now on."

A reasonable reading of "from now on" is that the reseed forces each device to renegotiate its state against the rebuilt server-side system rather than trusting a cached local sync token. If you repair the e-reader but leave the phone on the old cached state, you have rebuilt one end of the bridge and left the other end on the old foundation — which is exactly the scenario that produces the "it worked for two days and then broke again" complaint.

What to Check Before and After You Repair

Sync is a silent feature, so it is worth doing a small amount of bookkeeping rather than assuming the repair worked. Before you start, open the book you are mid-way through on your primary device and note the chapter and approximate percentage. Do the same on the second device. If the two positions already disagree, you have confirmed the bug and you now have a baseline to test against.

After the one-time repair on all devices, open the same book on each one in turn and let it sit connected to Wi-Fi for a moment. Then jump to a distinctive location — the start of a chapter is easiest to verify — and check whether the other device picks it up on its next sync check. Kobo e-readers sync on Wi-Fi checks rather than continuously, so give the second device a minute or two and a network connection before concluding anything.

Books with unusual metadata can still misbehave

One thing the rebuild does not change is metadata quality, and this is where a lot of sideloaded libraries get into trouble. Progress tracking depends on the device agreeing with the server about which book a position belongs to. If a file was converted from another format and arrived without a clean identifier — no ISBN, no consistent title and author strings, no stable internal identifier — the two devices can be reading byte-identical text while the service treats them as different books.

That is a file-hygiene problem rather than a sync problem, and it is worth fixing separately. If you manage a large library, the workflow described in our Calibre EPUB metadata guide covers cleaning up title, author, and series fields so that every device reports the same book identity. Readers who convert formats regularly will also want to check that their converted files carry the original identifier forward — our guide to EPUB formatting and conversion walks through what should survive a conversion and what routinely gets dropped.

Where the Kobo rebuild sits next to StoryGraph

It is easy to confuse this announcement with Kobo's StoryGraph integration, which we covered when it launched earlier this year in our Kobo StoryGraph integration guide. They are different systems solving different problems. StoryGraph receives a record of books you have finished — title, author, reading duration, date finished — and pushes that outward so your reading stats populate automatically. It is explicitly one-way, it fires on completion rather than continuously, and it does not carry your current page position.

The rebuilt system here is the opposite direction and a much finer grain: it is Kobo's own internal bookkeeping of where you are right now inside a book, plus your bookmarks and highlights, shared between devices you own. One is a social reading log; the other is the reason you do not lose your place. An active Kobo user with a StoryGraph account depends on both, and the two failing independently is exactly why the confusion happens.

Why Progress Sync Is Worth Caring About

The strategic backdrop is straightforward. Amazon's Kindle ecosystem keeps reading position in sync through WhisperSync, and it is one of the few features that genuinely locks readers in — losing your place across devices is annoying enough that people tolerate it rather than switch. Kobo has spent 2026 making a visible play for readers who want a more open ecosystem: expanded retail distribution at Best Buy in the United States, a firmware line that now ships EPUB-adjacent improvements and StoryGraph support, and a hardware lineup that now includes a genuine pocket-sized competitor to the Kindle.

None of that matters if the basics are unreliable. An open ecosystem that lets you carry your EPUB library between devices is a strong pitch, but the pitch assumes the software layer holding the reading experience together works quietly in the background. A syncing system that loses your place is a liability that no amount of format openness offsets, because the friction lands on the reader every single day rather than once at purchase.

There is also a maintenance dimension most people never think about. A broken sync stack makes a device feel disposable, which in turn makes people less willing to invest in keeping a proper library. If your reading position is unreliable, the file you own becomes interchangeable with a rented stream. Readers who care about building a DRM-free EPUB library specifically care about this distinction, because a library only has value if you actually keep using the devices that read it.

What This Signals for the Rest of 2026

Announcing a backend rebuild through a CEO's personal social account, with plain language instead of a press release, tells you Kobo treats this as a trust repair rather than a feature launch. That is the right instinct. Sync bugs are the kind of thing that never generate a dramatic headline but quietly erode confidence in an entire platform, and they are disproportionately damaging to a company whose pitch is "your books, on your devices, in an open format."

For readers, the practical takeaway is small and immediate: if you split your reading between a Kobo e-reader and the Kobo app, spend five minutes running the repair on every signed-in device today. It is a two-tap fix on the e-reader and a sign-out/sign-in on the phone. Then test it with the book you are currently reading, in the middle of a chapter, where a mismatch is obvious. Five minutes now is a better trade than discovering at bedtime that you have lost forty pages of progress.

For everyone else — single-device readers whose progress never drifted — the news is that a quiet, invisible weakness in the Kobo platform has been addressed before it became visible to you. That is the least dramatic possible outcome, and it is the one you want.