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format · deprecated

MOBI

MOBI is the legacy Kindle ebook format, retired by Amazon in 2022.

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What is a MOBI file?

An older Kindle-compatible ebook format derived from Mobipocket, superseded by AZW3 and EPUB.

Technical characteristics

Representation
binary
Compression
PalmDoc
Lossy
No
Open specification
No

History and origin

Introduced
2000
Created by
Mobipocket
  1. 2022Amazon stops accepting MOBI for Send to Kindle

Compatibility

    Applications: Older Kindle devices, Calibre.

    Advantages of MOBI

    • Works on very old Kindle hardware

    Limitations to know about

    • No modern CSS or layout features
    • Deprecated by Amazon
    • No support for embedded fonts

    When to use MOBI

    • Legacy Kindle libraries

    Convert MOBI files

    Recommended next step

    • Convert to EPUB

      Amazon retired MOBI in 2022 and modern Kindles accept EPUB, so EPUB is now the portable, future-proof choice.

      Trade-offs: Very old Kindle hardware still needs MOBI or AZW3.

      Learn about EPUB

    MOBI scores

    Deterministic scores calculated from the structured facts above. Identical facts always produce identical scores.

    Overall score

    32/100

    • Printing score

      62
      • lossless data means no compression artefacts appear at print resolution
      • only a narrow set of applications handles it

      Confidence 48% · evidence coverage 50%

    • Editing score

      51
      • lossless data survives repeated open-edit-save cycles without degrading
      • only a narrow set of applications handles it

      Confidence 45% · evidence coverage 63%

    • Photography score

      37
      • lossless data survives repeated open-edit-save cycles without degrading
      • it does not satisfy: small files are easy to email, message and upload
      • it stores data losslessly, so files stay large

      Confidence 44% · evidence coverage 44%

    • AI score

      36
      • lossless pixels avoid compression artefacts leaking into training data
      • the specification is proprietary or undocumented
      • only a narrow set of applications handles it

      Confidence 46% · evidence coverage 100%

    • Performance score

      35
      • it stores data losslessly, so files stay large
      • large lossless payloads cost bandwidth and memory

      Confidence 55% · evidence coverage 100%

    • Streaming score

      33
      • it stores data losslessly, so files stay large
      • large lossless payloads cost bandwidth and memory

      Confidence 57% · evidence coverage 50%

    • Compatibility score

      27
      • it does not satisfy: small files are easy to email, message and upload
      • a closed specification limits which managed services will touch it

      Confidence 54% · evidence coverage 50%

    • Archiving score

      18
      • the specification is proprietary or undocumented
      • it is marked legacy or deprecated in the knowledge graph

      Confidence 60% · evidence coverage 89%

    • Web score

      17
      • lossless payloads cost more bandwidth than the web usually justifies
      • the specification is proprietary or undocumented

      Confidence 49% · evidence coverage 67%

    • Longevity score

      15
      • it is marked legacy or deprecated in the knowledge graph
      • the specification is proprietary or undocumented

      Confidence 57% · evidence coverage 100%

    • Openness score

      13
      • the specification is proprietary or undocumented
      • implementing it may require permission from the vendor

      Confidence 47% · evidence coverage 100%

    What MOBI is recommended for

    Every conclusion below is derived from the structured facts on this page — nothing is written by hand.

    • Printing suitability71/100

      • Because lossless data means no compression artefacts appear at print resolution.

    What MOBI is not recommended for

    • Web suitability0/100

      • Because lossless payloads cost more bandwidth than the web usually justifies.
      • Because it does not satisfy: the specification is open, so tooling and CDNs implement it freely.

    • Everyday consumer usage0/100

      • Because it does not satisfy: small files are easy to email, message and upload.
      • Because it is a legacy format that recipients may struggle to open.

    • Open standards0/100

      • Because the specification is proprietary or undocumented.

    • Future-proofing0/100

      • Because it is marked legacy or deprecated in the knowledge graph.
      • Because proprietary control makes the long-term outlook dependent on one vendor.
      • Because a successor format already exists and is taking over its use cases.

    • Compression efficiency23/100

      • Because it stores data losslessly, so files stay large.
      • Because its codec generation predates modern entropy coding and block partitioning.

    • Software compatibility33/100

      • Because only a narrow set of applications handles it.

    • Licensing33/100

      • Because implementing it may require permission from the vendor.

    • Long-term archiving38/100

      • Because a closed specification puts readability at the vendor's mercy.
      • Because it is legacy or deprecated, so tooling support will keep shrinking.
      • Because a newer format already supersedes it, which shortens its support horizon.

    Migration paths

    • MOBI → EPUB

      Open standards improves by 100 points because the specification is published openly.

      Convert MOBI to EPUB

    Successors and legacy considerations

    Superseded by: AZW3.

    The knowledge graph marks MOBI as deprecated, so expect shrinking tooling support over time.

    AZW3 supersedes it in new work.

    It scores 38/100 for archiving: a closed specification puts readability at the vendor's mercy; it is legacy or deprecated, so tooling support will keep shrinking.

    Related to MOBI

    File extensions

    Alternatives

    Supported by

    Created by

    Compared with

    Succeeds

    Data quality

    Every claim on this page is classified as a verified fact, a derived fact or an assumption.

    Overall confidence
    80%
    Verification status
    verified
    Last reviewed
    2026-08-03
    Verified facts
    2

    2 classified claims backed by 1 source.

    • Convert Always editorial review — Convert Always

    Sources and review status

    Review status: verified · confidence 80%

    Last reviewed 2026-08-03 (revision 1).

    • Convert Always editorial review — Convert Always