The latest articles on DEV Community by Debpriya santra (@debpriya_santra_72b0ade20). https://dev.to/debpriya_santra_72b0ade20 https://media2.dev.to/dynamic/image/width=90,height=90,fit=cover,gravity=auto,format=auto/https:%2F%2Fdev-to-uploads.s3.us-east-2.amazonaws.com%2Fuploads%2Fuser%2Fprofile_image%2F4132428%2F8cc876e5-0ce1-46d6-a249-6e6b4de4837c.png https://dev.to/debpriya_santra_72b0ade20 en Debpriya santra Sat, 19 Sep 2026 06:02:10 +0000 https://dev.to/debpriya_santra_72b0ade20/building-a-zero-lag-client-side-python-visualizer-with-pyodide-webassembly-118o https://dev.to/debpriya_santra_72b0ade20/building-a-zero-lag-client-side-python-visualizer-with-pyodide-webassembly-118o <p>Understanding code execution, call stacks, and pointer mutations can be tricky—especially when debugging complex algorithms, recursion, or data structures like linked lists and trees.</p> <p>To solve this without server latency, I built <strong><a href="https://pyrunner-kfoc.onrender.com/" rel="noopener noreferrer">PyViz</a></strong>, a zero-lag, completely in-browser <strong>python code visualizer</strong> powered by WebAssembly (Pyodide).</p> <h3> Why PyViz? </h3> <p>Most online execution visualizers rely on backend servers to run Python code via isolated Docker containers. This introduces server latency, sandbox timeouts, and scalability limits.</p> <p>With PyViz:</p> <ul> <li> <strong>Client-Side WebAssembly Execution</strong>: Python runs directly inside your browser tab using Pyodide.</li> <li> <strong>Step-by-Step Python Execution Debugger</strong>: Move forward and backward through line-by-line execution states.</li> <li> <strong>Python Memory &amp; Call Stack Visualizer</strong>: Inspect active stack frames, local/global variable scopes, heap objects, and pointer references dynamically.</li> <li> <strong>LeetCode Python Visualizer Online</strong>: Perfect for testing recursion, binary tree traversals, and linked list operations when solving DSA interview problems.</li> </ul> <h3> How it Works Under the Hood </h3> <ol> <li> <strong>Dynamic UI Rendering</strong>: The frontend parses the step events and dynamically updates the editor highlight, stack frame list, variable tables, and memory heap pointers without full page re-renders.</li> </ol> <p>Try it out here: <strong><a href="https://pyrunner-kfoc.onrender.com/" rel="noopener noreferrer">Visualize Python Execution Online on PyViz</a></strong></p> <p><a href="https://media2.dev.to/dynamic/image/width=800%2Cheight=%2Cfit=scale-down%2Cgravity=auto%2Cformat=auto/https%3A%2F%2Fdev-to-uploads.s3.us-east-2.amazonaws.com%2Fuploads%2Farticles%2Fhsvn9chdz2h5pgsmyue2.png" class="article-body-image-wrapper"><img src="https://media2.dev.to/dynamic/image/width=800%2Cheight=%2Cfit=scale-down%2Cgravity=auto%2Cformat=auto/https%3A%2F%2Fdev-to-uploads.s3.us-east-2.amazonaws.com%2Fuploads%2Farticles%2Fhsvn9chdz2h5pgsmyue2.png" alt="Code Compiler and Visualizer UI" width="799" height="361"></a></p> <p>I’d love to hear your feedback or feature suggestions! What algorithms would you like to visualize next?</p> <p><a href="https://media2.dev.to/dynamic/image/width=800%2Cheight=%2Cfit=scale-down%2Cgravity=auto%2Cformat=auto/https%3A%2F%2Fdev-to-uploads.s3.us-east-2.amazonaws.com%2Fuploads%2Farticles%2Flncjv8d8ix0dya07by10.png" class="article-body-image-wrapper"><img src="https://media2.dev.to/dynamic/image/width=800%2Cheight=%2Cfit=scale-down%2Cgravity=auto%2Cformat=auto/https%3A%2F%2Fdev-to-uploads.s3.us-east-2.amazonaws.com%2Fuploads%2Farticles%2Flncjv8d8ix0dya07by10.png" alt="Website" width="800" height="363"></a></p> python webassembly algorithms webdev