Devin vs fx (2026): Which AI App Is Better?

Both are popular ai agents & automation. Here is how Devin and fx stack up on price, strengths and weaknesses, and which one we would pick.

Devin

Autonomous software engineer that ships pull requests

7.9 /10

Pricing: Paid from $20/mo

Pros

Works asynchronously on many tasks
Slack and GitHub native
Learns your repo over time

Cons

Compute costs add up
Needs well-scoped tasks to succeed

Visit Devin ↗

fx

Tiny, open-source native coding agent CLI built in Zig for research and embedding

6.5 /10

Pricing: Open source

Pros

Minimal, native binary with no heavy runtime dependency, making it easy to embed in other tools or pipelines
Fully open source, so its behavior can be audited and extended
Small footprint makes it a good base for research and experimentation with agent architectures

Cons

Deliberately minimal, so it lacks the polish, integrations, and ecosystem of larger commercial coding agents
Best suited to developers comfortable working with a CLI and Zig-based tooling rather than a point-and-click experience

Visit fx ↗

Devin vs fx at a glance

	Devin	fx
Editor score	7.9 / 10	6.5 / 10
Pricing model	Paid	Open source
Starting price	$20/mo	Free
Reader upvotes	0	0
Best for	coding agent, autonomous, pull requests	cli, coding agent, open-source

Our pick

Devin edges it with a score of 7.9 versus 6.5. Devin is the better fit if you value: works asynchronously on many tasks, slack and github native. Choose fx instead if you need: minimal, native binary with no heavy runtime dependency, making it easy to embed in other tools or pipelines, fully open source, so its behavior can be audited and extended.