fx vs oha

Which should you use? A side-by-side look at what each one does, who it suits, what it costs, how hard it is to set up, and where each falls short.

Open source · MIT

A terminal tool for viewing and processing JSON interactively.

Full review Website

oha

Open source · MIT

A command-line tool that sends many HTTP requests to a web server and shows live results.

Full review Website

The short answer

Choose fx if you need…

Developers who work with JSON output from APIs or log files in the terminal
People who want to explore a JSON document interactively instead of reading raw text
Users who prefer keyboard-driven terminal tools

Choose oha if you need…

Developers checking how an API or website handles many simultaneous requests
Backend engineers comparing performance before and after a change
People who prefer a terminal tool with a live view over reading raw output
Users who want to set a request rate limit or test over HTTP/2

Side-by-side

	fx	oha
Type	CLI	CLI
Price	Free and open source	Free and open source
Licence	MIT	MIT
GitHub stars	20.7k	10.7k
Setup difficulty	Beginner	Beginner
How you get it	Download the app	Install with a package manager
Main language	Go	Rust
Last code update	15 days ago	4 days ago

What each one is

fx

fx is a command-line program that lets you browse JSON data in an interactive terminal view and run processing on it. It is useful when raw JSON from an API or file is hard to read as plain text. The README is brief and points to fx.wtf for full documentation.

oha

oha is a command-line program that sends a large number of HTTP requests to a web address to see how it performs under load. While it runs, it shows a live terminal display with progress and results. It is written in Rust and is inspired by the older hey tool.

Best for

Developers who work with JSON output from APIs or log files in the terminal
People who want to explore a JSON document interactively instead of reading raw text
Users who prefer keyboard-driven terminal tools

oha

Developers checking how an API or website handles many simultaneous requests
Backend engineers comparing performance before and after a change
People who prefer a terminal tool with a live view over reading raw output
Users who want to set a request rate limit or test over HTTP/2

Strengths

Open source under the MIT license
Widely starred project with an active repository (last push listed as 2026-10-22)
Ships prebuilt binaries for Linux, macOS, and Windows

oha

Live terminal display shows progress while the test runs
Many options cover headers, bodies, authentication, TLS certificates and HTTP versions
Available through several package managers and as pre-built binaries for major operating systems

Not ideal for

People who need a graphical JSON editor, since fx runs in the terminal
Anyone needing details on specific processing syntax, since the README does not describe it and the documentation lives on the external site

oha

Testing a whole user journey across many steps, since the README describes sending requests to a URL rather than scripted scenarios
Anyone needing a graphical interface, since the tool is terminal-based
Testing live production systems without permission, because heavy load can cause outages

Trade-offs

The README is short and defers most details to the external documentation site
Install commands and processing syntax are not shown in the provided README

oha

The README describes some features as experimental, such as HTTP/3 support
Behavior differs from the similar hey tool in places, such as how -q is applied, so existing scripts may need changes
Large numbers of connections may require raising the system's open-file limit, as the README notes

Getting started

Download a release binary for your platform from the GitHub releases page

git clone https://github.com/antonmedv/fx

Step-by-step guide: how to use fx

oha

Install via Cargo

cargo install oha

Install on macOS with Homebrew

brew install oha

Step-by-step guide: how to use oha

Frequently asked questions

What is the difference between fx and oha?

fx: A terminal tool for viewing and processing JSON interactively. oha: A command-line tool that sends many HTTP requests to a web server and shows live results. fx suits developers who work with json output from apis or log files in the terminal, while oha suits developers checking how an api or website handles many simultaneous requests.

Are fx and oha free?

fx: Free and open source. oha: Free and open source.

Is fx or oha more popular?

fx has more GitHub stars (20.7k) than oha (10.7k). Popularity isn't the same as fit — check which one matches your use case above.

What are other alternatives to fx and oha?

Other options people compare them with include gron, Vegeta, http-server.

Keep comparing

oha alternatives fx vs gron oha vs Vegeta http-server vs oha

Built from our catalogue entries for both products: open-source details come from each project's README (AI-assisted, refreshed weekly) and GitHub data; AI-tool details are editorial. Spotted something wrong? Let us know from either product's page.