Helix Real-Time CRISPR Simulator

Stream edit DAG frames directly in the browser — no backend required.

Genome (FASTA or plain sequence) CRISPR guide (5' → 3') PAM pattern Mismatch tolerance Max candidate sites Indel window

CDS (optional) CDS start (1-based) CDS end (1-based) Strand Exons (start-end, comma-separated)

Speed (ms)

Transcript config (JSON) Load transcript JSON Transcript

Schema: { transcripts: [{ id, name, strand, cds_start, cds_end, exons: [[start,end], ...] }] } (1-based)

Outcome filters Intended (repaired) Indel / error No edit Other (cut/prime/flap/root)

Desired (intended/repaired) Undesired (any error/indel)

Only desired nodes

Only terminal nodes

On‑target Off‑target

Load a simulation…

Selection

Click a node to see details.

Comparison Mode (Experimental)

Run a second configuration to overlay edits side-by-side.

Guide A Guide B

PAM Mismatch tolerance

Awaiting comparison…