FB2 to MOBI Converter
Convert FictionBook (FB2) ebooks to MOBI for older Kindle devices and apps.
Complete the security check to begin
About Converting FB2 to MOBI
FB2 is an XML-based e-book format popular in Eastern Europe. It stores the whole book in a single structured XML file, which makes it easy to convert. When you need to move away from FB2, the usual reason is simple: limited reader support outside certain regions.
Converting your FB2 e-book to MOBI solves that. MOBI is a legacy Amazon Kindle e-book format. Although Amazon now prefers AZW3/KFX, MOBI remains widely compatible with older Kindle devices and apps. In practice you gain works on older kindles and reflowable text. PrivConvert runs the whole FB2-to-MOBI conversion in server memory and deletes your file the instant the MOBI is ready — nothing is stored, logged or reused.
When this conversion helps
- You need works on older Kindles
- You need reflowable text
- Sharing a FB2 e-book with someone whose software expects MOBI
Tips for best results
- Files up to 250 MB are supported, and you can batch-convert several FB2 files at once; each is processed privately and deleted immediately.
How to Convert FB2 to MOBI Online
Converting FB2 to MOBI with PrivConvert takes three quick steps and no software to install. What you gain with MOBI: works on older Kindles.
Drag and drop your file into the upload area, click to browse your device, or paste a URL to a file hosted online. You can upload files up to 250 MB and batch convert up to 20 files at once.
Once uploaded, the conversion from FB2 to MOBI starts automatically. The process runs entirely in an isolated environment - your data never leaves the secure pipeline.
Your converted file is ready instantly. Click the download button to save it to your device. The file is deleted from memory immediately after download.
A more private way to convert FB2 files
Plenty of sites convert FB2 files. Very few promise never to keep them — PrivConvert does, and backs it up with how the service is built.
We never keep a copy. Once your MOBI is delivered, both the original and the result are gone — there is nothing left to leak or misuse.
Every conversion runs in its own locked-down process with no network access, so files can never leak or interfere with one another.
Your files are handled entirely by automated code. No staff, partner or AI model ever reads, stores or trains on your data.
Files are processed in volatile memory (RAM) and purged the instant your download is ready — nothing is ever written to disk, cached or backed up.
FB2 vs MOBI - Format Comparison
| Feature | FB2 | MOBI |
|---|---|---|
| File extension | .fb2 | .mobi |
| Full name | FictionBook | Mobipocket eBook |
| Encoding | Text | Binary |
| Editable | Yes | No |
| Open standard | Yes | — |
| Supported by PrivConvert | Yes (as input) | Yes (as output) |
| Privacy-safe conversion | In-memory, zero storage | |
| Max file size | 250 MB per file | |
| Batch support | Up to 20 files simultaneously | |
Built for people who value their privacy
From one-off files to daily batches, thousands of people rely on PrivConvert precisely because it keeps nothing once the job is done.