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wtf is stormcrawler?

yforc/stormcrawler — explained in plain English

Analysis updated 2026-08-03 · repo last pushed 2026-06-09

Audience · developerComplexity · 4/5MaintainedLicenseSetup · hard

TL;DR

A toolkit for building web crawlers that can visit and download large numbers of web pages quickly and reliably. It runs on Apache Storm to distribute work across multiple computers for large-scale crawling.

Mindmap

mindmap
  root((repo))
    What it does
      Visits web pages
      Parses page content
      Follows links
      Fetches efficiently
    Tech stack
      Java
      Apache Storm
      Apache Maven
    Use cases
      Search engines
      Data pipelines
      Monitoring systems
    Audience
      Developers
      Organizations
    Setup
      Java 17 plus
      Apache Storm required
      Template generator

Code map

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filefunction / class

Why would anyone build with this?

REASON 1

Build a specialized search engine that crawls and indexes thousands of websites.

REASON 2

Monitor competitor pricing by crawling product pages across many sites on a schedule.

REASON 3

Collect news articles from multiple sources into a data pipeline for analysis.

REASON 4

Crawl web content at scale for research or data collection projects.

What's in the stack?

JavaApache StormApache Maven

How it stacks up

yforc/stormcrawler00kaku/gallery-slider-block04amanrajj/netwatch
Stars0
LanguageJavaScriptRust
Last pushed2026-06-092021-05-19
MaintenanceMaintainedDormant
Setup difficultyhardeasymoderate
Complexity4/52/53/5
Audiencedevelopergeneralops devops

Figures from each repo's GitHub metadata at analysis time.

How do you spin it up?

Difficulty · hard Time to first run · 1h+

Requires Java 17, Apache Maven, and a running Apache Storm cluster to operate.

Free to use, modify, and distribute for any purpose, including commercial use, as long as you include the license notice.

Wtf does this do

Apache StormCrawler is a toolkit for building web crawlers, programs that systematically visit and download pages from the internet. It's designed for projects that need to crawl large numbers of websites quickly and reliably, whether that's for a search engine, a data pipeline, or a monitoring system. At a high level, the project provides a set of building blocks that handle the common challenges of web crawling: deciding which URLs to visit, fetching pages efficiently, parsing their content, and following links to discover more pages. It runs on Apache Storm, which is software that lets you distribute work across many computers so you can scale up to handle bigger crawling jobs. You configure the crawler through text files that specify things like which sites to crawl and how to identify your crawler to the websites you're visiting. The main audience is developers or organizations building systems that need to collect web content at scale. A startup building a specialized search engine, a company that monitors competitor pricing across thousands of product pages, or a research team collecting data from news sites would all be typical users. It's not a tool for someone who just needs to scrape a single page, it's built for ongoing, large-scale crawling operations. Getting started requires some technical setup. You need Java 17 or higher, Apache Maven (a build tool for Java projects), and Apache Storm itself. The project provides a template generator that creates a starter project with sensible defaults, including the configuration files and a basic crawling setup. From there, you customize the configuration to target the sites you want to crawl. The project is mature and backed by the Apache Software Foundation, which means it has an established community, documentation, and even companies offering commercial support. It's written primarily in Java and released under the Apache License, so it's free to use and modify.

Yoink these prompts

Prompt 1
Set up a StormCrawler project using the template generator and configure it to crawl a single website, fetching pages and following internal links.
Prompt 2
Configure StormCrawler to respect robots.txt rules and set a custom user-agent string for my crawler in the configuration files.
Prompt 3
Build a distributed web crawler with StormCrawler that runs on Apache Storm across multiple worker nodes and stores fetched page content to disk.
Prompt 4
Customize StormCrawler's URL filtering and parsing pipeline to only crawl pages matching specific URL patterns on a target site.

Frequently asked questions

wtf is stormcrawler?

A toolkit for building web crawlers that can visit and download large numbers of web pages quickly and reliably. It runs on Apache Storm to distribute work across multiple computers for large-scale crawling.

Is stormcrawler actively maintained?

Maintained — commit in last 6 months (last push 2026-06-09).

What license does stormcrawler use?

Free to use, modify, and distribute for any purpose, including commercial use, as long as you include the license notice.

How hard is stormcrawler to set up?

Setup difficulty is rated hard, with roughly 1h+ to a first successful run.

Who is stormcrawler for?

Mainly developer.

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