What is json-perf-loader?

json-perf-loader is a plugin for webpack, a tool that bundles JavaScript code for web applications. Its job is to load JSON data files in a way that makes your app start up faster. The idea behind it comes from a finding by the V8 engine team (V8 is the JavaScript engine inside Chrome and Node.js): parsing a JSON string with JSON.parse is significantly faster than letting the JavaScript engine parse an equivalent JavaScript object literal written directly in code. The difference matters most for files 10 kilobytes or larger. When you add json-perf-loader to your webpack configuration and import a JSON file in your code, the loader checks the file size. If the file is at or above a configurable size threshold (defaulting to about 10 KB), it converts the import into a JSON.parse(...) call instead of a raw object literal. Smaller files below the threshold are left as-is. Setup involves installing the package from npm and adding a rule to your webpack config that points .json files at this loader with the size limit you want. The type: "javascript/auto" setting is required in the webpack rule to prevent webpack's own built-in JSON handling from interfering. The project is released under the MIT license.