About Schematic Viewer
Schematic Viewer is a free browser tool that opens schematic PDFs, highlights connected wires and finds every label and part with the same name. Why it exists, how it works and where its limits are.
What it does
Schematic Viewer is a web tool for opening schematic PDFs. Click a wire and every line and pin electrically connected to it is highlighted; labels and power symbols with the same name are gathered so you can step through them. You can search by reference or value and save the net and part lists as CSV.
- Supported files: PDFs exported from schematic programs such as KiCad, Altium, Eagle and OrCAD
- File handling: all analysis happens in your browser; files are never uploaded or stored on a server
- Cost: free, no sign-up
- Languages: Korean, English
Why it exists
A schematic received as a PDF is hard to trace without the original CAD files. Labels with the same name are scattered across pages, and a PDF reader's search finds text but can't tell you how far a wire reaches. Repairs, design reviews and study all spend a lot of time on this.
Schematic Viewer was built to cut that repetitive work. So that it can be used even for drawings that may not leave a company, it was designed from the start so that your file never leaves your device.
How it works
- The browser reads the PDF and extracts its lines (vector paths) and text (text layer), using Mozilla's open-source PDF.js.
- Line width, colour and shape separate wires from symbols, and end points and junctions are joined into nets.
- Text at wire ends is read as net labels, and text near parts as references and values. When the PDF also carries connection or part data — as Altium and OrCAD exports can — that data is used to correct the result.
- The result is drawn over the sheet, and the net under your click is highlighted.
Because connections are inferred from a drawing, the result is not as exact as the original netlist. Accuracy is scored against a set of public schematics with every change. Limits and fixes are listed in Supported files and troubleshooting.
Who runs it
An individual developer who works with electronics. The source code is on GitHub, and the site is served as static files from GitHub Pages — there is no server-side program or database.
Ads may be shown to cover running costs. They do not affect the tool's features or how files are handled; related cookies are explained in the privacy policy.
Get started
Open a schematic PDF, or try the example schematic first. New users may like the guide. Feedback and bug reports are welcome on the contact page.