How to Validate JSON and Find Syntax Errors

Validating JSON means checking that it parses correctly according to JSON's syntax rules — nothing more, nothing less. Here's how to actually do it and make sense of what comes back.

Step-by-Step: Validating Your JSON

1. Copy the JSON you want to check — from an API response, a config file, or anywhere else.
2. Paste it into the validator.
3. Read the result. Valid JSON gets confirmed immediately; invalid JSON gets flagged with a specific error.
4. If it's invalid, check the reported location — most validators point to a line and character position, not just "somewhere in this file."

Reading an Error Message Correctly

A typical validation error looks something like "Unexpected token } at position 142" or "Expecting ',' delimiter at line 8, column 3." These aren't vague — the position tells you precisely where the parser gave up. It's worth noting that the reported location is where the parser detected the problem, which is sometimes one character after the actual mistake (a missing comma is detected at the next value, not at the comma's absent position) — so if the flagged spot looks fine, check just before it too.

Validating Isn't the Same as Fixing

A validator tells you that something is wrong and roughly where — it doesn't rewrite your JSON to fix it for you, and it shouldn't. Auto-correcting invalid JSON would mean guessing at your intent, which risks silently changing your data instead of just flagging the problem. Treat the validator as a precise error locator, then fix the issue yourself with that information in hand.