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NCBI BLAST

Similarity search against every public sequence database.

Server

NCBI BLAST

NCBI · blast.ncbi.nlm.nih.gov

Does
Similarity search against every public sequence database.
Access
Free
Limits
Shared queue; large batches are rate limited

Use this when

Almost any "what is this sequence" question. For very large batches, run BLAST+ locally or use DIAMOND — the web queue is not built for thousands of queries.

Open NCBI BLAST

External tool. We link, we don’t host — nothing you enter on Biology 101 reaches them.

About this tool

The reference sequence similarity search. Nucleotide, protein and translated searches against the full NCBI holdings.

Science last reviewed .