We provide QIIME 2 taxonomy classifiers for multiple regions of SSU and LSU:

CAUTION: The SILVA taxonomy does not include species and is only curated down to the genus level. Therefore, species information may be unreliable. The data used for species information is actually the organism name provided by the sequence's author when submitting it to one of the INSDC databases.

The classifiers for the current SILVA release can be downloaded here. The directory structure references the QIIME 2 version that we used to create the classifier. Usually, they are compatible with other QIIME 2 versions. For details, see the compatibility matrix.

A README file containing background information on each classifier can be found alongside it. This includes information such as parameters, the tools used and their versions, and the required citations for the classifier. Please additionally cite the classifiers you use by their DOI. Currently, the DOI can only be found in the .doi file in the same directory as the classifier.

Additional information for 138.2: Please note that the QIIME 138.2 classifiers provided by SILVA differ slightly from those provided by the QIIME 2 team. We have used unaligned sequences truncated at the rRNA gene boundaries, whereas the QIIME 2 team used raw sequences, which may extend beyond the rRNA gene. From release 144 onwards, SILVA will only provide the truncated sequences. For consistency reasons, we have trained the 138.2 classifiers using the truncated sequences. This should not affect the classification results, but we want to be transparent about it.

These are the classic QIIME 2 classifiers you probably have used in the past. Our uniform classifiers do not include species information.

These are experimental classifiers that have been adapted for use in specific habitats in order to improve species-level classifications. See Kaehler et al. for details. When using these classifiers, ensure that your sample is from the selected habitat. Using a classifier for a different habitat will produce incorrect results. We also recommend analysing your sample using one of our uniform classifiers to verify that it does not include sequences from unexpected genera.

CAUTION: The SILVA taxonomy does not include species and is only curated down to the genus level. Therefore, species information may be unreliable. The data used for species information is actually the organism name provided by the sequence's author when submitting it to one of the INSDC databases.

As of 2025.10, QIIME 2 supports signing classifiers. Starting with SILVA 144, we sign the classifiers we provide. The name of our signature is SILVA-Pipeline-Official. To verify the signature you also need our public PGP key. For details how to verify the signature, please see the QIIME 2 documentation.

-----BEGIN PGP PUBLIC KEY BLOCK-----
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=OsdQ
-----END PGP PUBLIC KEY BLOCK-----