How Loudwalk imports Anki (.apkg & .colpkg), keeps FSRS-6, and exports back to Anki

If you have spent years building an Anki collection with tens of thousands of reviews, you should never trust it to an app that resets your intervals or locks your data in. Here is exactly how Loudwalk reads, schedules, and exports your collection — and how you can verify it yourself.

Disclosure: This guide is published by Loudwalk (iOS 26 or later and Apple silicon Mac · macOS 26 or later). Free and built-in Anki methods are covered first with links to Anki’s official manuals. Loudwalk is independent of Anki and is not affiliated with Ankitects.

What comes across when you import an Anki file

When you import an Anki Collection Package (.colpkg) or Deck Package (.apkg) — whether exported with Anki’s modern default format or with “Support older Anki versions” ticked — Loudwalk imports:

• Every deck, note, and card, preserving due dates, intervals, lapses, and current learning steps (a card on its second learning step in Anki arrives on its second step, not reset to the first).
• Every historical review row (revlog) you have ever done, so your FSRS stability, difficulty, streak, and retention statistics are continuous from day one.
• Your deck presets: custom FSRS-6 weights/parameters, desired retention, learning and relearning steps, and daily new/review limits.
• Your notetypes and media: custom HTML and CSS templates, cloze deletions, Anki’s native Image Occlusion (including rotated masks), pictures, and [sound:] audio files.

How FSRS-6 parity is verified against Anki 26.08.1

Saying “supports FSRS” is easy; matching Anki’s actual v3 scheduler behavior across learning steps, day boundaries, fuzz, and load balancing is where most implementations drift.

Loudwalk’s scheduler is held to answers recorded directly from a real Anki 26.08.1 installation:

• 750 answer transitions across new, learning, review, and relearning cards
• 2,862 fuzz draws (using the same MIT-licensed rand RNG family so interval fuzz lands on the exact same day)
• 8 full queue snapshots testing day rollovers and daily limits

Every single transition must replay identically in Loudwalk’s test suite before a release can be built. Both the recorded fixture and the Python script that generated it from Anki are published openly so you can inspect or re-run them yourself: /anki-golden.json and /anki-golden.py.

How iCloud Drive sync and local backups work

Going back to Anki: the round-trip export

Loudwalk does not lock you in. On the Mac app, Backup & sync → Going back to Anki writes a .colpkg or an .apkg containing:

• All of your cards, notes, media, tags, and flags
• Every review you completed in Loudwalk (both spoken on a walk and tapped on screen) alongside the historical reviews you originally imported
• Each card’s updated due date, interval, and FSRS-6 memory state (stability and difficulty)

Because the exporter lays Loudwalk’s work over a copy of the Anki file you imported, deck presets, tags, and flags come back as they left, and any card you never reviewed in Loudwalk comes back byte-for-byte identical. We verify this round-trip against Anki itself using /anki-export-check.py, which builds a collection in Anki, runs reviews through Loudwalk, imports the exported package back into Anki, and verifies every card’s deck, due date, FSRS memory state, review rows, and Anki’s own Check Database.