0x

What it is

0x is an open-source tool designed for generating flamegraphs with a single command, primarily for JavaScript applications. It leverages V8's built-in profiler to capture CPU usage and visualize it in an interactive flamegraph format. This tool is particularly useful for developers looking to optimize performance by identifying bottlenecks in their code. With its MIT license, 0x is freely available and maintained by a community of contributors.

Single-command setup for generating flamegraphs in JavaScript applications.

When it fits — and when it doesn’t

Known weaknesses

Each one links to the public issue, changelog or docs page it came from, where we have one.

1. 01

   Limited to JavaScript applications

   The tool is built around V8's profiler, which is specific to JavaScript.

2. 02

   No recent updates

   Last commit was on 2025-07-07.

3. 03

   Requires understanding of flamegraphs

   The tool outputs flamegraphs, which require interpretation.

What it does well

• Easy to use with a single command

  The tool's description emphasizes 'single-command flamegraph profiling'.

• High community engagement

  3548 stars and 46 contributors on GitHub.

• Open-source with MIT license

  Both GitHub and npm data confirm the MIT license.

Pricing

Free tier

Yes

Paid from

—

Model

Flat rate

Enterprise plan

No

Pricing last confirmed Sep 30, 2026.