================================================================================ ARTICLE: Open-Source Fact-Checking Tools for Journalists URL: https://omniscient.news/blog/open-source-fact-checking-tools Published: 2026-03-15 Updated: 2026-03-22 Category: Fact-Checking Tags: open source fact-checking, free journalism tools, fact-check tools, InVID, ClaimBuster ================================================================================ Free and open-source tools for professional fact-checking: InVID/WeVerify, ClaimBuster, Google Fact Check Tools, Hoaxy, and more. A complete guide for journalists on a budget. The Open-Source Fact-Checking Ecosystem Professional fact-checking has historically required expensive subscriptions to news databases, proprietary research tools, and significant staff time. The emergence of a robust open-source and free-tier fact-checking ecosystem has dramatically democratised access to professional-grade verification tools — enabling independent journalists, local news organisations, and community fact-checkers to deploy verification capabilities that were previously available only to well-resourced major newsrooms. Core Free Fact-Checking Tools InVID / WeVerify Browser Extension (Free) is the most widely used free visual verification tool. It provides: reverse video search by keyframe extraction; video metadata analysis (showing upload history and original source); geolocation analysis of video and images; magnification tools for detecting digital manipulation; and integration with Google, Yandex, and TinEye for reverse image search. Used by AFP, BBC Verify, Reuters, and professional fact-checkers globally. Google Fact Check Tools (Free) includes the Fact Check Explorer — a searchable database of fact-checks from IFCN-certified organisations globally — and the Fact Check Markup Tool, which enables publishers to add ClaimReview schema to their fact-check articles. The Fact Check Explorer is invaluable for quickly identifying whether a specific claim has already been fact-checked. ClaimBuster (Free API) is an academic tool from the University of Texas at Arlington that automatically identifies check-worthy factual claims in text, ranked by their "check-worthiness" score — helping fact-checkers prioritise claims when analysing speeches, debates, or press conferences with many assertions. Hoaxy (Free), developed by Indiana University, visualises how claims and fact-checks spread across social media networks — showing the relative reach of original misinformation versus the corrections that debunked it. Invaluable for understanding the sociological dynamics of specific misinformation campaigns. Whois.domaintools.com (Free basic tier) enables domain registration lookup — revealing who owns a website, when it was registered, and whether the registrant matches the claimed publisher identity. First-line verification for unfamiliar sources. Frequently Asked Questions Q: What is the best free fact-checking tool? A: InVID/WeVerify is consistently rated the most valuable free fact-checking tool by professional fact-checkers for visual media verification. For textual claims, Omniscient AI's free tier and Google's Fact Check Explorer are the most useful starting points. Q: What is ClaimBuster? A: ClaimBuster is a free AI tool from the University of Texas at Arlington that analyses text to identify and rank factual claims by their 'check-worthiness' — how verifiable, specific, and consequential they are. It helps fact-checkers prioritise which claims to investigate from lengthy transcripts or articles. Q: Is InVID still available in 2026? A: Yes. InVID/WeVerify continues to be developed and maintained by a consortium including AFP, Deutsche Welle, and several European universities. The browser extension is available for Chrome and Firefox and is free to use. Q: What is the Google Fact Check Explorer? A: Google Fact Check Explorer is a free searchable database of fact-checks from IFCN-accredited and Google-recognised fact-checking organisations globally. Searching a claim or topic shows all relevant fact-checks already published by professional fact-checkers worldwide — avoiding duplicate work. Q: What is Hoaxy? A: Hoaxy is a free visualisation tool from Indiana University's Observatory on Social Media (OSoMe) that shows how specific articles, claims, and their fact-check responses spread through Twitter/X networks — enabling researchers and journalists to understand the relative reach and velocity of misinformation versus corrections.