VCF to CSV Converter

The VCF to CSV Converter processes VCF variant data into a tabular CSV format for downstream analysis in spreadsheets, databases, and BI tools. It accepts VCF input either as a file upload or pasted text, and outputs a CSV with core fields such as CHROM, POS, ID, REF, ALT, QUAL, FILTER, INFO, and FORMAT plus per-sample columns when requested. For multi-allelic records, ALT values can be expanded into separate rows or retained as a single field depending on configuration. INFO fields can be expanded into individual columns or kept as a single encoded column. Advanced options enable selective column mapping, choosing the order of CSV columns, converting numeric INFO values to numeric types, and applying simple filters to include only records matching criteria. The tool does not perform variant annotation; its focus is format conversion and tabular ready data.

Under the hood, the tool uses a robust streaming parser to handle large VCF files without loading them entirely into memory. It validates VCF syntax, normalizes numeric values, and ensures proper CSV quoting. When expanding INFO, parses key=value pairs and places them into dedicated columns if selected. If sample data expansion is enabled, FORMAT/sample fields can be surfaced as separate columns or omitted for a compact table. Output delimiter can be set to comma or tab for TSV compatibility. The converter also preserves header lines from the VCF file (starting with #) when exporting to CSV, so downstream processes retain context.

Target users include genomics researchers, clinical diagnostics teams, data engineers, and bioinformaticians who need to integrate variant data into reports, dashboards, or pipelines. Unique value drivers include dual input modes (upload or paste), flexible INFO expansion, controlled multi-allelic handling, and streaming processing that scales to large files. The tool emphasizes data integrity by producing well-formed CSV, gracefully handling errors, and preserving header information for reproducibility.