A guide-RNA designer for CRISPR base editing.

CRISPR base editing technologies enable the direct conversion of DNA bases (C to T/A/G) without inducing double-strand breaks of DNA by the fusion of cytidine deaminase with deactivated Cas9 (dCas9) or Cas9 nickase.

PAM Type

CRISPR-Cas orthologues for base editing

Target Genome

Organism Type



Send request for a new organism.

Please specify how to download the reference genome 2bit or FASTA files of the organism.

Target Sequence

Insert any sequence(s) where you want to search for CRISPR base editing targets (raw sequence or FASTA format, maximum 1000 chars):

Or, upload a FASTA-formatted file containing target sequence(s) (maximum 1 KiB):

crRNA length
(length of target without PAM)

Base editing type:



  1. Komor AC et al., Nature 533, 420–424 (2016).
  2. Kim YB et al., Nature Biotechnology 35, 371-376 (2017).
  3. Nishida K et al., Science 353, aaf8729 (2016).
  4. Nicole MG et al., Nature 551, 464-471 (2017).