diff --git a/docs/assets/README_GSM6326543.png b/docs/assets/README_GSM6326543.png
new file mode 100644
index 0000000..9c2b95d
Binary files /dev/null and b/docs/assets/README_GSM6326543.png differ
diff --git a/pyproject.toml b/pyproject.toml
index e4a211a..d957ffe 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -39,6 +39,9 @@ dev = [
 notebooks = [
     "jupyterlab",
 ]
+converters = [
+    "hic-straw"
+]
 test = [
     "pytest",
     "pytest-cov",
diff --git a/scripts/hic2hseq.py b/scripts/hic2hseq.py
new file mode 100644
index 0000000..72c6f30
--- /dev/null
+++ b/scripts/hic2hseq.py
@@ -0,0 +1,150 @@
+"""Convert a .hic file into HoloSeq hseq format.
+
+HoloSeq hseq format is described in holoSeq/docs/HoloSeqOverview.md
+
+# Conversion from .hic format to hseq
+
+This script converts a .hic file into the HoloSeq hseq format using the
+[straw](https://github.com/aidenlab/straw/) library. The hic format
+stores a symmetric matrix, and the converter only provides the lower
+triangle of counts to distinguish it from asymmetric matrices.
+
+## Usage:
+
+1. Install the package with the required dependencis:
+   ```
+   pip install holoSeq[converters]
+   ```
+
+2. Download a .hic file. For example, in the series
+   [GSE207951](https://www.ncbi.nlm.nih.gov/geo/query/acc.cgi?acc=GSE207951),
+   click on "(custom)" in the table at the bottom, check a single .hic
+   file, then click the "Download" button. Untar it.
+
+3. Run the conversion script:
+   ```
+   python3 scripts/hic2hseq.py input.hic output.hseq.gz
+   ```
+
+4. Use the output file in the HoloSeq environment to display the matrix:
+   ```
+   panel serve scripts/holoseq_display.py --show --args --inFile output.hseq.gz --size 1000
+   ```
+
+## Example Data:
+
+A pre-converted HTAN file for [GSM6326543 is
+available (530MB)](https://pub-867b121072f54b4a9eecdf01cd27246b.r2.dev/GSM6326543_A001C007.hg38.nodups.pairs.hseq.gz).
+
+See hseq conversion output of GSM6326543 at `holoSeq/docs/assets/README_GSM6326543.png`
+"""
+
+import gzip
+import logging
+import os
+import argparse
+from typing import List
+
+import hicstraw
+
+logger = logging.getLogger(__name__)
+logging.basicConfig(
+    format="%(asctime)s - %(name)s - %(levelname)s - %(message)s", level=logging.INFO
+)
+
+
+class GzipOut:
+    """Context manager for writing gzipped files."""
+
+    def __init__(self, fn: str):
+        self.fn = fn
+        self.f = gzip.open(fn, "wb")
+
+    def write(self, x: str) -> None:
+        self.f.write(str.encode(x))
+
+    def __enter__(self):
+        return self
+
+    def __exit__(self, *_) -> None:
+        self.f.close()
+
+
+def cumulative_sum(x: List[int]) -> List[int]:
+    if not x:
+        return x
+    y = [x[0]]
+    for n in x[1:]:
+        y.append(n + y[-1])
+    return y
+
+
+def convert_hic_to_hseq(hicfn: str, ostream: GzipOut, max_chrom: int, title: str) -> None:
+    """Convert a .hic file into HoloSeq hseq format.
+
+    Parameters:
+        hicfn (str): Path to the input .hic file.
+        ostream (GzipOut): GzipOut instance for writing the output.
+        max_chrom (int): Maximum number of chromosomes to include.
+        title (str): Title for the output matrix.
+    """
+    if not os.path.isfile(hicfn):
+        raise FileNotFoundError(f"Input file '{hicfn}' does not exist.")
+
+    hic = hicstraw.HiCFile(hicfn)
+    chroms = hic.getChromosomes()
+
+    if max_chrom < 1 or max_chrom > len(chroms):
+        max_chrom = len(chroms)
+
+    resolution = min(hic.getResolutions())
+    offsets = cumulative_sum([c.length for c in chroms])
+    cnames = [c.name for c in chroms]
+
+    ostream.write(
+        f"@v1HoloSeq2D\n@title {title}\n"
+        + "".join(f"@H1 {chrom} {offset}\n" for chrom, offset in zip(cnames, offsets))
+    )
+
+    xbase = 0
+    for i, cx in enumerate(chroms[:max_chrom]):
+        ybase = 0
+        for cy in chroms[: i + 1]:
+            logger.info(f"Processing {cx.name} vs. {cy.name}")
+
+            try:
+                for result in hicstraw.straw(
+                    "observed", "NONE", hicfn, cx.name, cy.name, "BP", resolution
+                ):
+                    x = xbase + result.binY
+                    y = ybase + result.binX
+                    ostream.write(f"{x} {y}\n" * int(result.counts))
+            except Exception as e:
+                logger.error(f"Error processing {cx.name} vs. {cy.name}: {e}")
+
+            ybase += cy.length
+        xbase += cx.length
+
+
+if __name__ == "__main__":
+    ap = argparse.ArgumentParser(description=__doc__)
+    ap.add_argument("hicfile", help="Input .hic format filename or URL")
+    ap.add_argument("hseqgz", help="Output filename (will be gzipped)")
+    ap.add_argument("--title", default="", help="Matrix title (default: input hic path)")
+    ap.add_argument(
+        "--max-chrom",
+        type=int,
+        default=0,
+        help="Maximum number of chromosomes to convert (default: all)",
+    )
+
+    argv = ap.parse_args()
+
+    argv.title = argv.title or argv.hicfile
+
+    try:
+        with GzipOut(argv.hseqgz) as ostream:
+            convert_hic_to_hseq(argv.hicfile, ostream, argv.max_chrom, argv.title)
+        logger.info("Conversion completed successfully.")
+    except Exception as e:
+        logger.error(f"Failed to convert .hic to HoloSeq format: {e}")