UltraJSON vs orjson

Side-by-side — pricing, strengths, tradeoffs, and fit.

UltraJSON

A fast JSON decoder and encoder written in C with Python bindings.

orjson

Fast, correct JSON library for Python.

At a glance

Open SourceFree Tier
● Established·From $0
Open SourceFree Tier
● Established·From $0

Overview

One-liner

A fast JSON decoder and encoder written in C with Python bindings.

One-liner

Fast, correct JSON library for Python.

Maturity

Established

Maturity

Established

Open source

✓ Yes

Open source

✓ Yes

Pricing

Free tier

✓ Available

Open source — free to use

Free tier

✓ Available

Open source — free to use

Starts at

$0

Starts at

$0

Model

Flat rate

Model

Flat rate

Enterprise

✕ None

Enterprise

✕ None

Best for

✓ Best for

Developers working on high-performance Python applications that require fast JSON parsing and generation.
Projects where the standard json module's speed is a bottleneck.

✓ Best for

Developers working on high-performance Python applications that require frequent JSON operations
Projects needing to optimize the speed of JSON parsing and generation in their critical paths

Not ideal for

✕ Not for

Applications where ease of use is prioritized over performance, as UltraJSON requires more setup than the built-in json module.
Scenarios where compatibility with non-Python environments is necessary.

✕ Not for

Applications where simplicity is prioritized over performance
Scenarios where the overhead of integrating a new library outweighs potential performance gains

Strengths

↑ Strengths

High performance JSON encoding and decoding
Written in C for speed
Python bindings for easy integration

↑ Strengths

High performance JSON parsing and generation
Written in Rust for speed
Supports Python's datetime objects directly

Weaknesses

↓ Weaknesses

Limited language support
Does not handle complex JSON data structures well
Lack of advanced features compared to other libraries

↓ Weaknesses

Limited language support
Complex setup for non-standard configurations
Small community support
Full UltraJSON profile →Full orjson profile →