Pixel-by-pixel Comparison - Rust + N-API in Node

The fastest path: native Rust compiled to a Node addon via N-API, ~3-4× faster than odiff. @blazediff/core-native works on file paths - it decodes PNG, JPEG, and QOI itself (in parallel) and can write the diff image straight to disk. Reach for it in Node test runners and CI where you have files and want maximum throughput.

Installation


npm install @blazediff/core-native


pnpm add @blazediff/core-native


yarn add @blazediff/core-native


bun add @blazediff/core-native

Examples

Basic Comparison

Image 1

Image 2

Result


import { compare } from "@blazediff/core-native";
 
const result = await compare("3a.png", "3b.png");
 
if (result.match) {
  console.log("identical");
} else if (result.reason === "pixel-diff") {
  console.log(`${result.diffCount} pixels differ (${result.diffPercentage.toFixed(2)}%)`);
} else if (result.reason === "layout-diff") {
  console.log("dimensions differ");
}

Custom Threshold

Image 1

Image 2

Result


import { compare } from "@blazediff/core-native";
 
const result = await compare("3a.png", "3b.png", undefined, {
  threshold: 0.5,
  antialiasing: true,
});

Write Diff Image

Image 1

Image 2

Result


import { compare } from "@blazediff/core-native";
 
// Pass an output path to render the diff visualization to disk.
// Format is inferred from the extension (PNG, JPEG, QOI).
const result = await compare("3a.png", "3b.png", "diff.png");

Want a verdict on what changed, not just how many pixels? Pass interpret: true or use the dedicated Image Difference Analysis → example. Full options in the API reference →.