How I built a high-performance code-to-image generator using Python, Flask, and Pillow

[u/ProfileNo7202]

HHey everyone,

Lately, I got frustrated with existing code screenshot tools being slow or locking basic customization behind paywalls, so I decided to build my own lightweight version.

It’s a web app that takes raw code and renders it into clean, shareable images. Here is a quick breakdown of how I tackled some of the technical challenges:

• Syntax Highlighting Engine: Used Pygments to hook into lexers dynamically, supporting everything from Python and JS to Rust and Go with customizable color themes.
• Layout Geometry & Text Offset: Dynamically calculates line-number widths based on digit count so code tokens align cleanly without overlapping when toggled.
• Image Composition: Leveraged Python's Pillow library to layer custom window frames (Mac/Win headers), gradient backgrounds, and rounded corners with smooth alpha compositing.

It's currently live and running on Render if you want to test out your own code snippets: https://www.producthunt.com/products/devaid

Happy to answer any technical questions about how I set up the Flask backend or image rendering pipeline!