I try to submit an article with citations to arxiv.org, and the TeX output says

Package biblatex Warning: File 'main.bbl' is wrong format version - expected 2.8.

Okay, so my local biblatex/biber combination is incompatible with arxiv's. Can anyone tell me which biblatex/biber combination produces BBL format 2.8?

  • 1
    biblatex 3.8 corresponds to biber 2.8 (See the 'biber/biblatex compatibility matrix' in the biblatex documentation)
    – leandriis
    Commented Feb 16, 2018 at 18:52
  • Does this produce BBL format 2.8? Because biber version and bbl format are not tied to one another. Commented Feb 16, 2018 at 18:53
  • 1
    I am not sure but to me they always seemed to be corresponding. Nevertheless, you might find some useful information regarding the usage of biber/biblatex and arxiv here: tex.stackexchange.com/a/358920/134144
    – leandriis
    Commented Feb 16, 2018 at 19:20

4 Answers 4


If you are looking for help with biblatex and Biber for arXiv uploads, have a look at https://github.com/plk/biblatex/wiki/biblatex-and-the-arXiv and Biblatex and arxiv, error. This answer here mainly addresses the question in the title at face value.

In general, the .bbl file version need not correspond to either the biblatex or the Biber version. The same goes for the .bcf version. The .bbl and .bcf versions can be stepped up with a biblatex/Biber release, but they need not be. In practice that means that the versions trail behind the biblatex/Biber versions and there is only an approximate correspondence between them and the actual package versions.

biblatex 3.5, 3.6 and 3.7 all need .bbl format version 2.8. The corresponding Biber versions are 2.6 (for biblatex 3.5 and 3.6) and 2.7 (for biblatex 3.7). biblatex 3.4 needs .bbl version 2.7, biblatex 3.8 has .bbl version 2.9.

So the newest combination that works with .bbl 2.8 is biblatex 3.7/Biber 2.7. As far as I know that is indeed the version arXiv is using after the February 2017 update Biblatex and arxiv, error.

You can find historic releases of biblatex and Biber at GitHub (https://github.com/plk/biblatex/releases, https://github.com/plk/biber/releases) and SourceForge (https://sourceforge.net/projects/biblatex/files/, https://sourceforge.net/projects/biblatex-biber/files/biblatex-biber/).

  • As of 2021 at least, .bbl files version is now needed to be 3.1 The 2021 version of TexLive with updated packages currently produces this, but only if you use the biber backend of biblatex. The bibtex backend still produces version 2.8 and so does not work. Make sure you are not using backend=bibtex if you are having problems with this now.
    – user32157
    Commented Dec 1, 2021 at 15:06

I managed to workaround the problem doing the following:

  1. Upload the Latex project in overleaf.
  2. Compile your project in Overleaf.
  3. In the view window, go to the option "Other logs & Files" and download the ".bbl" file. At this time, when I checked the ".bbl" file of Overleaf, it is exactly the version 2.8 of Biblatex.
  4. Rename the "output.bbl" (that you've go from compilation in Overleaf) to the same filename of the ".tex" file which you want to submit to Arxiv.
  5. Upload ".tex", ".bbl" and other supporting files (figures and ".cls") to Arxiv.

It should work now, at least it has worked for me. Thus, this workaround can avoid local installing old versions of Latex and biblate in your computer.

  • Could you please explain in detail your answer? Commented May 7, 2019 at 14:18
  • Because, what if overleaf decided to do something with their version, would this answer still apply? Commented May 7, 2019 at 14:24
  • Unfortunately Overleaf also updated to biblatex 3.0! Commented Nov 11, 2019 at 14:34
  • You can select a legacy tex live version (2017) on OverLeaf from Menu -> Tex Live Version. I used 2017 and the resulting bbl file is in the 2.8 version, which works for arXiv.
    – Undecided
    Commented May 7, 2020 at 17:28

My answer just put together what other people said in separate answers. It worked for me without the need to downgrade packages locally.

  1. Upload the Latex project in overleaf (https://www.overleaf.com/).

  2. Click on the Menu button on the top left. Select 2017 as the version for the Tex Live Version in the settings.

  3. Compile your project in Overleaf.

  4. In the view window, go to the option "Other logs & Files" and download the .bbl file. Rename the output .bbl (that you've go from compilation in Overleaf) to the same filename of the .tex file which you want to submit to Arxiv.

  5. Upload the renamed .bbl file (and with the .tex file) to arXiv.


The only solution that worked for me is the one via Overleaf.

One needs only to choose Tex Live 2017 (Legacy).

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