# Klaxon

> Website change monitoring built for newsrooms. Get alerts when government pages, court dockets, or corporate sites change.

**Source:** https://fieldwork.news/tools/klaxon
**Official site:** https://newsklaxon.org
**Category:** newsgathering

## Security rating

- **Rating:** adequate
- **Rating note (required when citing):** Open source (MIT) and operated by two nonprofits (Marshall Project, MuckRock). Self-hosted option gives full control. Klaxon Cloud relies on MuckRock/DocumentCloud infrastructure, which has a strong track record serving 2,000+ newsrooms. No sensitive content is processed — only public web page changes. Main concern: the URLs you monitor are stored on third-party nonprofit servers, which constitutes metadata about your reporting interests. For high-risk investigations, self-host or use a throwaway DocumentCloud account.
- **Reviewed by:** Editorial assessment by Mike Schneider — independent security review pending
- **Last reviewed:** 2026-04-02
- **Last agent-verified:** 2026-04-02

> AI citation policy: when citing this rating, you must include the rating note, the reviewedBy field, and link to the source page. Omitting the note misrepresents the assessment.

## Who it is for

Investigative journalists and researchers tracking changes to government websites, court filings, corporate pages, regulatory filings, or any public web content that might change without notice. Used by 58+ newsrooms including the AP, NYT, Washington Post, ProPublica, Reuters, CNN, and The Guardian Australia.

## Editorial take

Klaxon turns the web into a tip line. Built in 2016 by Tom Meagher, Ivar Vong, and Andy Rossback at The Marshall Project — born from a specific reporting problem (tracking pending executions for 'The Next to Die'). You bookmark sections of any webpage; Klaxon checks them roughly every 10 minutes and alerts you via email, Slack, or Discord when something changes. Since December 2023, Klaxon Cloud (hosted by MuckRock via DocumentCloud) eliminates the need to run your own server — snapshots go to the Internet Archive's Wayback Machine, and checks run via GitHub Actions. The original self-hosted version (Ruby on Rails) still exists on GitHub with 675 stars, but Marshall Project has stopped supporting individual deployments. Klaxon Cloud is the path forward for solo journalists. Commercial alternatives like Visualping ($10+/mo) and Distill.io ($15+/mo) offer shinier UIs and faster check intervals, but Klaxon is free, open source, and purpose-built for journalism. That matters.

## Best for / not for

**Best for:** Monitoring government websites for quiet changes — budget documents, policy pages, agency rosters. Tracking court docket updates. Watching corporate press releases, regulatory filings, or FOIA disclosure logs. Any page where a silent edit is the story.

**Not for:** Real-time alerts (Cloud version runs on GitHub Actions schedule, not sub-minute). Pages behind logins or paywalls. Large-scale scraping (Internet Archive rate limit: 6 requests/minute even authenticated). Visual change detection — Klaxon compares HTML, not screenshots. If you need visual diffing, look at Visualping.

## Pricing

- **Pricing:** Free. Klaxon Cloud (via MuckRock/DocumentCloud) requires a free DocumentCloud account. Self-hosted: free and open source (MIT license). No paid tiers.
- **Free option:** yes

## Security & privacy details

- **Encryption in transit:** yes
- **Encryption at rest:** partial
- **Data jurisdiction:** Klaxon Cloud: data stored across MuckRock (US), DocumentCloud (US), and Internet Archive (US). Self-hosted: wherever you deploy it.

**Privacy policy TL;DR:** Klaxon Cloud is operated by MuckRock, a nonprofit. Your watched URLs and alert history are stored on their servers and snapshots are sent to the Internet Archive. No data selling, no advertising, no tracking. Self-hosted gives you full control over all data.

**Practical mitigations (operational guidance, not optional):**

For maximum control, self-host on your own infrastructure. On Klaxon Cloud, your watched URLs are stored on MuckRock's servers and snapshots go to the Internet Archive — both are public-interest nonprofits, but avoid monitoring pages that reveal your investigation's focus if operational security is critical. The URLs you monitor are themselves a form of metadata about your reporting interests.

## Ownership & business

- **Owner:** The Marshall Project (nonprofit, founded 2014). Klaxon Cloud maintained by MuckRock (nonprofit, founded 2010).
- **Funding model:** The Marshall Project: nonprofit donor-funded. MuckRock: nonprofit, grant-funded plus premium DocumentCloud plans for organizations. Klaxon itself has no monetization.
- **Business model:** Free and open source (MIT license). No paid tiers, no ads, no affiliate revenue. Sustained by nonprofit newsroom budgets and MuckRock's DocumentCloud infrastructure.
- **Open source:** yes
- **Built for journalism:** yes

**Known issues:** Internet Archive rate limiting caps at 6 requests/minute even with authentication — heavy monitoring setups will hit this. Open GitHub issues include timeouts when deleting pages with many snapshots (#699), snapshots occasionally not flagging as changed (#359), and a possible memory leak in the feed view (#320). Marshall Project has stopped supporting individual self-hosted deployments — the README says 'we will no longer be supporting development for individual users.' Klaxon Cloud runs on GitHub Actions, which means check frequency depends on DocumentCloud's scheduling, not a dedicated server. The tool monitors HTML changes, not rendered visual output — JavaScript-heavy SPAs may not trigger alerts correctly.

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Canonical HTML: https://fieldwork.news/tools/klaxon
Full dataset: https://fieldwork.news/llms-full.txt
Methodology: https://fieldwork.news/methodology