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ujson Explained: How to Make Python JSON Parsing Much Faster

Learn how ujson speeds up JSON parsing in Python for APIs, logging, and data pipelines, with simple examples you can drop into real projects today.

Josh Wenner's avatar
Josh Wenner
Feb 18, 2026
∙ Paid

JSON is one of those things we use all the time without really thinking about it. APIs return it. Config files are written in it. Logs, payloads, scraped data, cached responses, all JSON. Most of the time, we just use Python’s built in json module and keep moving.

And honestly, that’s fine. Until it’s not. That’s where ujson comes in.

Ujson, short for UltraJSON, is a fast JSON library written in C and built for performance. It does the same job as Python’s standard json module, but it runs noticeably faster, especially when you are working with large chunks of data or parsing JSON over and over again in a loop.

Welcome to ujson. Check out other 3 Random Articles here.

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The easiest way to think about ujson is as a drop in upgrade. The concepts are the same. The usage feels the same. You just spend less time waiting on JSON to finish its work.

What I like most about ujson is how little it asks from you. There is no new way of thinking about JSON. No complicated setup. You still load, dump, serialize, and deserialize data the same way you always have.

The real difference is that ujson is tuned for speed, which makes it a great fit for data pipelines, web services, scraping jobs, and any script where performance actually matters.

In this article, we are going to look at ujson and then walk through three practical functions that show where it’s good and how you can start using it right away.

If you work with APIs, scrape data, or move a lot of structured data around, this is one tool you will be glad you know about.

Let’s get you set up with a quick terminal run:

pip3 install ujson

If you spend most of your day in the terminal like I do, this one is going to be fun.

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