BAM Header Viewer – Analyze & Export BAM Metadata Online

About BAM Header Viewer

The BAM Header Viewer is a powerful, secure, and free online tool designed for bioinformaticians and researchers. It allows you to instantly inspect the header section of Binary Alignment Map (BAM) files directly in your web browser. Unlike other tools that require uploading massive files to a server, this tool processes everything locally on your device using modern web technologies.

BAM files are the standard format for storing large-scale sequence data. The header contains critical metadata such as the format version, sorting order, reference sequences (chromosomes), and the command-line programs used to generate the file. Accessing this information usually requires command-line tools like samtools, but our viewer makes it accessible with a simple drag-and-drop interface.

How to Use

1. Select your file: Drag and drop a .bam file into the upload area, or click to select one from your computer.
2. Automatic Processing: The tool will read the beginning of the file and decompress the header block on the fly.
3. View Results: Instantly see a summary of the file's metadata, including version, sort order, and reference sequences.
4. Analyze & Export: Switch between the structured table view, raw text view, and JSON view. You can export the header data for documentation or further analysis.

Features & Tips

• Zero Uploads: Your data never leaves your computer. We use the browser's DecompressionStream API to read the compressed BAM file locally.
• Fast & Lightweight: Designed to handle large files by only reading the necessary header bytes, ensuring instant results even for multi-gigabyte files.
• Export Options: Unique to this tool, you can export the parsed header as a structured JSON file or a standard text file.
• Tip: Use the "JSON View" to easily copy-paste metadata into your lab notebook or analysis scripts.

Frequently Asked Questions