Free online GRAPHMLZ to PNG converter

PNG is needed when a mind map or flowchart must be viewed in an image viewer, inserted into a document, or shared without requiring graph-editing software. Converting a GRAPHMLZ file rasterizes its graph layout into a static image.

What the GRAPHMLZ format is

GRAPHMLZ is a compressed GraphML file used to store nodes, edges, labels, styling, and layout data for graphs, mind maps, and flowcharts. It is commonly created or opened by yEd Graph Editor and other applications based on GraphML or yFiles technology.

The format is normally a GraphML XML document compressed with gzip. Unlike PNG, it retains editable graph structure: individual nodes and connectors can be moved, renamed, restyled, or connected to other nodes after opening.

What the PNG format is

PNG is a lossless raster image format suitable for diagrams containing text, lines, and areas of flat color. It opens on nearly every operating system and can be embedded in presentations, documents, websites, and email.

PNG preserves the rendered appearance without requiring the recipient to install yEd, but it does not retain editable nodes, edges, GraphML metadata, hyperlinks, or layout information. It supports transparency and avoids the compression artifacts associated with JPEG.

How to convert GRAPHMLZ to PNG

Using yEd Graph Editor

1. Install and open yEd Graph Editor.
2. Choose File → Open and select the .graphmlz file. yEd normally decompresses and reads the format directly.
3. Check the layout, labels, page boundaries, and any clipped content in the graph view.
4. Choose File → Export, select PNG as the output format, and specify the destination filename, such as flowchart.png.
5. Set the export area and scale or image dimensions. Use a higher scale or larger pixel width when the PNG will be printed or displayed in a document.
6. Confirm the export and open the resulting PNG in an image viewer to check small labels and connector lines.

If the file does not open directly

Because GRAPHMLZ is gzip-compressed GraphML, decompress a copy first with a gzip utility. For example, on systems with the gzip command, run gzip -dk diagram.graphmlz; this creates diagram.graphml while preserving the original. Open the resulting .graphml file in yEd and export it through File → Export.

You can also convert the file for free on 101convert.com without installing software.

Quality and compatibility

PNG export produces a fixed-size raster image, so text can become difficult to read if the graph is exported at a small resolution. Increase the export scale or dimensions rather than enlarging the PNG afterward.

Very large graphs may create large PNG files or exceed limits in image viewers. If the diagram is intended for later editing, keep the original GRAPHMLZ file alongside the PNG; the image is only a visual rendering and cannot reliably be converted back into the original graph structure.

Fonts unavailable on the export computer may be substituted, changing text width and potentially affecting label placement. Verify font availability and inspect the exported image before distribution.