I built a JSON viewer because the most popular one betrayed its users
The incident In January 2026, JSON Formatter — the Chrome extension used by 2M+ developers — pushed an update that injected a donation popup from a service called "Give Freely" on checkout pages. W...

Source: DEV Community
The incident In January 2026, JSON Formatter — the Chrome extension used by 2M+ developers — pushed an update that injected a donation popup from a service called "Give Freely" on checkout pages. Without warning. Without consent. Developers reported seeing unexpected UI while entering credit card information. Some thought their browser was compromised. Security teams flagged it internally. Hundreds of 1-star reviews followed within days. I'd been using JSON Formatter daily for years. Like most of you. The decision I'd been wanting to build a better JSON viewer for a while. The landscape was frustrating: JSON Formatter: great basics, but minimal features, and now... this. JSON Viewer (tulios): richest feature set, but last updated December 2020. Not MV3 compatible. Breaking in newer Chrome versions. No extension handles JSON, YAML and XML in the same tool natively. The Give Freely incident was the signal I needed. I started building in January 2026. What I built JSONVault Pro is a Chrom