TikkunTech - EU Hackathon Targeting Online Antisemitism Brings More Than 100 Experts to Brussels

BRUSSELS – Leading tech and policy experts gathered alongside Jewish community representatives in Brussels this week to develop novel solutions to the most pressing challenges in the battle against online antisemitism. Working in multidisciplinary teams across three topical tracks (content moderation, AI and language technologies, and fostering Jewish life), participants designed and tested practical, rights-based tools to counter antisemitism and support Jewish life online.

WJC’s Technology and Human Rights Institute (TecHRI) played a leading role in bringing the event together alongside its partner, the Institute for Strategic Dialogue (ISD), as part of the European Commission project 'Support to prevent and counter illegal hate speech, in particular online'. TecHRI Executive Director Yfat Barak-Cheney participated in the opening panel alongside Katharina von Schnurbein, the European Commission’s coordinator on combating antisemitism and fostering Jewish life, laying the landscape of online hate to inspire solutions for the current trends. Among other things, the WJC facilitated the parallel AI red-teaming session and oversaw the development of participant teams before moderating the closing high-level segment and award ceremony.

The Developmental Tracks:

Content moderation: Teams worked on solutions to detect antisemitic content across online platforms, developed tools for reporting and monitoring, and apps for tracking how anti-Jewish hate speech and incitement to violence migrate from fringe spaces to mainstream platforms.

AI and language technologies: Teams created solutions for examining the errors produced by AI moderation tools, including bias in LLM-based hate speech detection, hallucinations and false positives. They used AI and LLM capacities to create additional content online, analyze content and enable users to understand antisemitism when it appears on social media feeds and understand how accurately and fairly AI models represent Jewish history and culture.

Fostering Jewish life: Teams took a broader approach, as Jewish community representatives collaborated with technical experts to develop tools to support Jewish life both in the real world and online, empower smaller communities and create connection between Jewish people worldwide.

In parallel, a dedicated AI red-teaming track led by the WJC and its partners brought community representatives and subject matter experts together to identify biases, harmful outputs and weaknesses in AI safeguards. Its sample findings, presented during the closing high-level segment, showed that seven leading large language models, tested in eight languages, consistently described Iran-linked terrorist groups such as Hamas and Hezbollah less negatively than other categories of terrorist organizations, frequently calling them “resistance organizations.” A second experiment found that the same model could give opposite answers on whether a conflict constituted genocide, depending on the identity of the user. The findings will be compiled into a report for the European Commission.

The Hackathon Winners

At the conclusion of the two-day gathering which will inform the EU Strategy on Combating Antisemitism and Fostering Jewish Life (2021-2030), European Commissioner for Internal Affairs and Migration Magnus Brunner presented awards to the three winning teams. The first-place prize supported by TikTok will include a visit to the Trust and Accountability Center, and second and third place prizes supported by Meta to continue developing of their initiatives:

First prize: 4Sight App
The challenge: Antisemitic narratives and jargon emerge on niche and fringe platforms before spreading to mainstream ones. Mainstream platforms often only learn of them once the new narratives have already spread.

The solution: An application for experts, CSOs, and trusted flaggers that uses AI to spot new antisemitic terms on fringe platforms such as 4chan and tracks when they begin to appear on X. Each emerging term is reviewed by a human expert, who can then alert platforms to new threats immediately, before they spread.

Second prize: L’chaim App
The challenge: Since the October 7th attacks, Jews across Europe feel increasingly unsafe and isolated and are turning to their communities. But especially for young and mobile people, finding a community can be difficult.

The solution: The L’chaim app matches users with Jewish events and with each other based on common interests and preferences, including religious observance, and enables them to meet safely. Users verify their identity, private events require the organizer’s approval, and members can vouch for people they know, building a web of trust.

Third prize: Kavannah Browser Extension
The challenge: Users scrolling through threads on X or Meta platforms regularly encounter disinformation and manipulative content, including antisemitic narratives, with little way of judging what is accurate or whether responding will only amplify it.

The solution: With one click, the Kavannah browser extension empowers users to analyze a post. Using AI, Kavannah fact-checks it against information sources and presents a score based on the context it is missing, the manipulation techniques it uses and whether it is antisemitic under the IHRA Working Definition. It also advises whether engaging would only amplify the post and can draft a Community Note in line with the platform’s guidelines.

Commissioner Brunner, who served as event patron, said, “In Europe, we believe innovation must serve people. Innovation shapes our societies. Europe’s strength lies in showing that technological leadership and the protection of fundamental rights can go hand in hand.”

Calling the Hackathon “an important milestone” in advancing the strategy’s goals, Katharina von Schnurbein, who served as chair of the competition’s jury, noted that “As the world’s largest gathering on this issue, it combined the vibrant atmosphere of a digital Maccabiah with a shared determination to shape our common future.”

Emphasizing the responsibility of governments and international institutions to invest in innovative solutions that protect Jewish life in Europe, World Jewish Congress President Ronald S. Lauder stated, “As digital platforms are a central battleground in the fight against antisemitism, we need technology to be part of the solution. Initiatives like TikkunTech, backed by the European Commission, demonstrate what is possible when we bring together ingenuity, expertise, and political will. When Jewish communities are secure, society as a whole is safer.”

Why This Work Matters Now

The Hackathon forms part of the WJC TecHRI’s broader mission to ensure that emerging technologies are developed and deployed in ways that protect human rights and use technology for the benefit of vulnerable communities.

Nine in ten Jewish respondents to the EU Agency for Fundamental Rights’ latest survey had encountered antisemitism online in the previous year. Generative AI is now compounding the problem, reproducing antisemitic bias, distorting historical fact and giving conspiracy narratives new reach, while online hate continues to spill over into real-world violence against Jewish communities.

TikkunTech builds on TecHRI's growing body of work examining the intersection of artificial intelligence, online hate, and human rights. In June 2026, the WJC convened more than 45 antisemitism experts, academics, and civil society representatives in New York for a dedicated red-teaming event aimed at identifying and mitigating antisemitic bias in AI systems.

About the World Jewish Congress Technology and Human Rights Institute (TecHRI):

The World Jewish Congress Technology and Human Rights Institute (TecHRI) works to address the opportunities and challenges posed by emerging technologies through the lens of human rights, combating antisemitism and hate, and fostering responsible innovation.