What is Katana?
Katana is an open-source web crawling and spidering framework written in Go and built by ProjectDiscovery. It crawls in a standard fast HTTP mode or a headless Chromium mode for JavaScript-rendered pages. It can extract endpoints from JS files, apply regex-based scope rules, and dedupe results by content similarity, with output in plain text, JSON, or JSONL, plus ML-based classification for login, error, and captcha pages. It ships as a CLI binary, a Docker image, and an importable Go library under the MIT license.
Our verdict
Katana fits teams that want a fast, code-integrated crawler to embed in Go tooling or run as a CLI or Docker job. Its headless mode and ML-based page classification cover cases a plain HTTP crawler misses. The tradeoff is that it's fully self-managed, with no hosted or GUI option, and building from source needs a recent Go 1.26+ toolchain.
Categories:
Crawling frameworks give engineering teams full control over their pipeline: where it runs, how it scales, and what it collects. The trade is that anti-bot work and infrastructure become your problem rather than a vendor's, which is why they pair well with a proxy network.
