JSON tool silently corrupted large integers in browser; three of four pages left unguarded

A developer at a JSON repair platform discovered that their browser-based tools were silently mangling large integers — such as distributed-system snowflake IDs — without any error or warning. The root cause is a fundamental JavaScript limitation: numbers beyond 2^53-1 lose precision when passed through JSON.parse, with no way to recover the original value afterward. While the platform's server-side API had a pre-parse guard that rejected such inputs with a 422 error, the client-side browser versions were calling JSON.parse directly, bypassing that protection entirely. The team uncovered the gap not through user complaints but by manually testing every tool with oversized numbers, finding three out of four browser pages were affected. The issue reflects a broader, long-standing industry problem — Twitter, Stripe, and even the pandas library have each had to implement their own workarounds for the same class of precision-loss bug.