calibre Conversion Settings Not Saving: How to Fix It

If calibre conversion settings are not saving, the program may not actually be forgetting your changes. calibre stores conversion options at more than one level, and previously saved settings for an individual book can override the defaults under Preferences. Bulk conversions can add another layer, while the selected output format, output profile, source file, plugins, and library state can make the result look as though an option was ignored. The safest approach is to reproduce the symptom with one book, identify which settings calibre actually used, and remove only the stale settings responsible for the problem.

1. Confirm the Symptom With a Small Safe Test

Start with a controlled test instead of repeatedly converting an important book. Choose one setting that produces an obvious result, such as a large margin, a changed output profile, or a clear font-size adjustment. Avoid testing several options at once because you will not know which setting affected the output.

1. Select one book in the calibre library.
2. Open Convert books and choose Convert individually.
3. Confirm the input and output formats at the top of the dialog.
4. Click Restore defaults before changing anything.
5. Change one easily recognizable conversion option.
6. Complete the conversion and inspect the newly created output format.
7. Open the individual conversion dialog again and check whether the changed option is still displayed.

If the option is still shown and another conversion reproduces the intended result, calibre is saving the per-book setting correctly. Stop changing global preferences. The earlier unexpected result probably came from another book's stored settings, a different output format, or the wrong copy of the converted file.

If the option remains visible but the output does not reflect it, examine the conversion job log and the source document. If the option disappears immediately, test whether calibre can write to its configuration and library locations.

1.1 Test With a Newly Added Book

A newly added book is especially useful because it normally has no stored conversion history in that library. Add a small, unprotected EPUB, HTML, DOCX, or other supported file that you are permitted to convert. Set the desired defaults under Preferences > Conversion, then convert the new book without customizing its individual dialog.

Success means the new book inherits the current defaults. If it does, the global defaults are working and the original title almost certainly has stale per-book conversion settings. If even the new book uses unexpected options, concentrate on global defaults, the selected output format, plugins, or configuration write access.

2. Understand How calibre Stores and Reuses Conversion Options

The most important fact in this calibre troubleshooting process is that global conversion defaults and per-book conversion settings are not the same thing. Settings under Preferences > Conversion provide the starting defaults for books that do not already have saved conversion options. After you convert a particular book, calibre remembers the final settings used for that book. Those stored per-book settings can take precedence the next time you convert it.

This behavior explains the common pattern where a user changes a default, converts an older title, and sees the old result again. The default may have saved successfully, but the selected book is still loading its own conversion history.

2.1 Saved Defaults Versus Current Dialog Changes

Changes made in an individual conversion dialog belong to the selected book after the conversion runs. They do not automatically become the defaults for every future book. Conversely, changing a preference does not necessarily replace options already stored for books that were converted before.

• Preferences defaults: Starting values for new conversions without overriding book-specific settings.
• Individual dialog settings: Options remembered for the selected library record after conversion.
• Bulk conversion settings: Options applied to the selected batch and then saved for the affected books.

If you want one book to follow the latest defaults, open its individual conversion dialog and select Restore defaults. Change only what that book specifically needs, then run the conversion. Success means reopening the dialog shows the intended values and the resulting file reflects them.

2.2 Reset Conversion Options for One Book

Select the affected book, open Convert individually, and click Restore defaults. Review the input and output formats before proceeding because available options and their defaults can vary by format. Run the conversion instead of merely closing the dialog.

After the job finishes, reopen the dialog. The values should now match the defaults plus any deliberate changes you made. Stop troubleshooting if repeated conversions of that book consistently use those values.

2.3 Remove Hidden Stale Settings From Multiple Books

When many older books exhibit the problem, resetting them individually is inefficient. Select the affected books and open the bulk metadata editing dialog. Near the bottom, use the option that removes stored conversion settings. This clears the saved per-book conversion history for the selected records without requiring you to delete the books or rebuild the entire library.

Use this option carefully. It removes intentional book-specific adjustments as well as stale ones. Test it on two or three expendable records first. Success means those records load the current conversion defaults the next time they are converted.

2.4 Check Bulk Conversion Precedence

Bulk conversion combines several sources of settings. calibre starts with the defaults from Preferences, may apply saved settings for each book, and then applies options selected in the bulk conversion dialog. The bulk dialog therefore can override book-specific values for settings available there. Metadata and input-format-specific options require extra attention because they are not all exposed in the same way during bulk conversion.

Look near the upper-left area of the bulk conversion dialog for the option controlling whether saved settings for individual books are used. If a mixed batch produces inconsistent results, disable reuse of individual settings or clear the stored settings before testing again. Convert together only books that genuinely need similar treatment.

Success means books in the batch receive the same intended settings where applicable. Once a small batch works, stop adjusting options and process the remaining comparable titles.

3. Check the Output Format, Profile, Metadata, and Result You Are Viewing

Sometimes calibre saves the options correctly, but the user checks a different format or expects a setting to affect an area it does not control. Verify the conversion path from source to result before treating the symptom as a saving failure.

3.1 Confirm the Input and Output Formats

The conversion dialog displays the input format and output format at the top. A book can contain several formats, such as EPUB, PDF, and AZW3. calibre may use a different source than the one you expected, and each output format exposes different options.

Choose the intended input explicitly and convert to a clearly identified output. If that output already exists, note the job completion time or remove only the old output format before creating a fresh one. Do not delete the entire book record.

Success means the format shown in the conversion job matches the format you open afterward. Stop if the correct newly generated file contains the expected change.

3.2 Separate Output Profile From Preferred Output Format

The output profile in the conversion page setup tells calibre how to optimize dimensions and related characteristics for a type of device. The preferred output format under interface behavior affects choices such as which format is preferred when viewing, saving, or sending books. These controls serve different purposes.

Changing the preferred format does not automatically rewrite a book, and changing the output profile does not guarantee that calibre's viewer or a connected device will open the newly converted format. Confirm both settings independently:

• Select the desired output format in the conversion dialog.
• Choose an appropriate output profile, or use a generic profile when no device-specific optimization is needed.
• Verify which format the viewer, save action, or device-send action selects.
• Remove or rename an older external copy if it could be mistaken for the new result.

Success means the generated format, selected profile, and file you inspect all match the test plan.

3.3 Check Metadata and Source File Limitations

Conversion metadata normally comes from the calibre library record, but some input-specific behavior and source structures can affect the output. For example, a source file may contain embedded styles that dominate visible formatting, while malformed markup can produce unpredictable layout. A fixed-layout or image-based source may not respond to text options as a normal reflowable book would.

Test the same setting with a simple newly added book. If it works there, the setting is being saved and the original source is the limiting factor. At that point, inspect or repair a copy of the source with calibre's editor when the format is editable. Do not keep changing saved defaults to compensate for one unusual file.

3.4 Rule Out Viewer and Device Confusion

The calibre viewer can retain reading position and presentation preferences, while a physical reader may apply its own fonts, margins, line spacing, or publisher-style controls. Sending a book can also select a preferred format that differs from the format you just converted.

Open the exact converted format from the book's format list or save that single format to a new local folder. If the local file is correct but the device display is not, the conversion setting was saved successfully. Check the device's reading controls, supported format, and the format calibre actually sent. USB mode matters only if calibre cannot update or replace the file on the device; it does not control how conversion options are stored in the library.

4. Check Permissions, Cloud Sync, Plugins, and Library State

Operating system issues are less common than stale per-book settings, but they become relevant when changes disappear across every book, preferences repeatedly revert, or calibre reports database errors.

4.1 Verify Write Access

Make sure your user account can write to both the calibre configuration location and the active library folder. On Windows, avoid placing a working library in a protected system folder. On macOS and Linux, check ownership and permissions if the library was copied from another account or restored as an administrator.

Do not solve the problem by routinely running calibre as an administrator or root. That can create files owned by a different account and make later access more confusing. Instead, move a test library to a normal user-owned local folder and try the controlled conversion again.

Success means settings remain after closing and reopening calibre, and the same book retains its intended conversion options.

4.2 Pause Cloud Sync During the Test

A calibre library stored inside a live cloud-synchronization folder can experience conflicts if the synchronization application modifies or locks library files while calibre is running. Antivirus or backup software can cause similar temporary contention.

For diagnosis, create a small local library outside OneDrive, Dropbox, iCloud Drive, network storage, and synchronized folders. Do not move the primary library casually. Use Library > Switch/create library to create an empty test library in a local user folder, then add one test book.

If settings save reliably there, the original environment is implicated. Stop modifying calibre conversion options and address synchronization, permissions, or storage reliability instead.

4.3 Temporarily Disable Relevant Plugins

Only investigate plugins if the problem occurs during a plugin-controlled conversion, device transfer, metadata workflow, or specialized output process. A standard conversion that fails in the same way with plugins disabled points elsewhere.

Disable one relevant third-party plugin at a time, restart calibre when requested, and repeat the same one-setting test. Keep a record so you can restore the original configuration. Success means the problem disappears only when a particular plugin is disabled. Update, reconfigure, or remove that plugin rather than changing unrelated calibre defaults.

4.4 Check the Library Without Deleting It

If the issue affects one library but not a clean local test library, use calibre's library maintenance tools to check the affected library. Back it up before performing repairs. Do not delete metadata.db, manually rearrange book folders, or create a new production library until the controlled test establishes that the library is involved.

5. Use Conversion Logs and Debug Output

Logs can show whether calibre used the value you selected. This is more reliable than judging from appearance alone.

5.1 Read the Conversion Job Details

After conversion, click the jobs indicator or rotating icon near the lower-right corner of the calibre window. Open the completed conversion job and inspect its log. The actual options used appear near the beginning of the log.

Search for the setting you changed, the input format, output format, and output profile. If the log shows the intended value, calibre saved or applied it and the remaining issue lies in the source, output capabilities, viewer, device, or file selection. If the log shows an old value, return to the per-book and bulk-setting steps.

Success means the log and dialog agree. At that point, stop resetting preferences and investigate the stage where the expected visual result is lost.

5.2 Generate Conversion Debug Output

For difficult formatting cases, use the conversion dialog's debug option and choose an empty folder. calibre can save intermediate files from multiple stages of its conversion pipeline. Comparing those stages helps distinguish an input parsing problem from a later structure, styling, or output problem.

This tool is useful when the log confirms the correct setting but the output remains wrong. It is not usually necessary for a simple stale per-book setting.

5.3 Run calibre in Debug Mode

Advanced users can restart calibre in debug mode from the Preferences menu or with the documented keyboard shortcut. The command calibre-debug -g also launches the graphical interface with diagnostic output when calibre's command-line tools are available.

Use debug mode when settings revert across a clean local library, a plugin appears involved, or the interface reports unexplained errors. Device-detection debugging is relevant only when the correct converted file is not being recognized or transferred to a connected reader. It will not repair stored conversion options.

6. Run a Clean Temporary Test Before Reinstalling

Reinstalling calibre usually does not remove per-book conversion settings stored with library data, so it often fails to solve this symptom. A clean temporary test gives more useful information with less risk.

1. Create a new empty library in a local, user-owned folder.
2. Add one small, legally usable test book.
3. Set one conversion default.
4. Convert the book and inspect the job log.
5. Close calibre completely and reopen it.
6. Convert the same book again and verify the setting.
7. Add a second fresh book and confirm that it inherits the default.

If both books behave correctly, calibre itself is working. Return to the original library and remove stale per-book settings only from affected titles. If the clean library fails too, test configuration-folder permissions, plugins, security software, and debug output before reinstalling.

Do not delete your main library, mass-reset every preference, or change multiple system settings at once. Stop as soon as one controlled test consistently survives a restart and produces the intended output.

7. Quick Fix Checklist

• Test one obvious option on one book.
• Confirm the correct input and output formats.
• Click Restore defaults in the individual conversion dialog.
• Remember that per-book settings can override Preferences defaults.
• Remove stored conversion settings through bulk metadata editing when several books are affected.
• Review whether bulk conversion is reusing individual book settings.
• Distinguish the output profile from the preferred output format.
• Open the exact newly converted file rather than an older copy.
• Inspect the completed job log for the actual options used.
• Test a newly added book in a clean local library.
• Check write permissions only if settings revert across books or restarts.
• Investigate device behavior only when the local converted file is correct.
• Use debug output for source-specific formatting failures.
• Reinstall only after a clean temporary test also fails.

8. Frequently Asked Questions

8.1 Why does an old book ignore my new conversion defaults?

calibre probably stored conversion settings for that individual book during an earlier conversion. Those settings can take precedence over the defaults in Preferences. Open the individual conversion dialog, select Restore defaults, and convert again.

8.2 Does changing an option in Convert Individually update every book?

No. The resulting settings are associated with the selected book. Set general defaults under Preferences > Conversion, then clear existing per-book settings where you want older records to inherit those defaults.

8.3 Why do books in the same bulk conversion produce different results?

The books may contain different saved conversion histories, input formats, metadata, or source structures. Check whether the bulk conversion is reusing stored settings for individual books. Clear those settings or disable their reuse for a controlled batch.

8.4 Will reinstalling calibre clear saved conversion settings?

Not necessarily. Reinstalling the application may leave the library and its stored book information intact. Reset or remove per-book conversion settings first, and use a clean temporary library to determine whether the installation is actually involved.

8.5 Why is the device showing old formatting after a successful conversion?

You may have sent a different format, left an older copy on the device, or encountered device-side reading preferences. Save and inspect the exact new output locally. If it is correct, verify the preferred format, send action, device file, and reader presentation controls.

8.6 How can I prove which settings calibre used?

Open the completed conversion job from the jobs indicator and read the log. The actual conversion options appear near the top. When the log shows the intended values, stop changing saved settings and investigate the source file or the application used to view the result.