I built JSONChecker because I was tired of staring at cryptic JSON syntax errors from APIs and config
  files. You know the pain – "SyntaxError at line 847" but good luck finding what's actually wrong in a
  wall of JSON.

  Why I built this:
  • Spent too many hours debugging malformed JSON from third-party APIs
  • Existing tools either crashed on large files or gave unhelpful error messages
  • Wanted something that could actually fix common issues automatically

  What it does:
  • Real-time validation with precise error highlighting
  • Pattern-based auto-repair (fixes missing quotes, trailing commas, bracket mismatches)
  • Visual diff showing exactly what changed
  • Handles large files without browser freezing (learned this lesson the hard way)

  Technical details:
  • Built with Next.js, runs entirely client-side (no data sent to servers)
  • Uses Web Workers for processing large files without blocking UI
  • Custom safety mechanisms to prevent infinite loops on malformed input
  • Rule-based repair engine using heuristics rather than simple regex

  The auto-repair feature works surprisingly well on common JSON errors. I've tested it with real-world
  malformed JSON from various APIs and it catches most issues developers encounter daily.

  Try it with some intentionally broken JSON – paste in something with missing quotes or trailing commas
  and watch it fix itself.

  Would love feedback from fellow developers who debug JSON regularly. What other features would make this
   more useful for your workflow?