Reading API Responses Without Losing Your Mind

You hit an API endpoint. The response comes back. It looks like this:

{"users":[{"id":1,"name":"John","email":"john@example.com","settings":{"notifications":true,"theme":"dark","language":"en"}},{"id":2,"name":"Jane","email":"jane@example.com","settings":{"notifications":false,"theme":"light","language":"es"}}],"meta":{"total":2,"page":1}}

Good luck finding that one field you need.

This is what 90% of API debugging looks like. Minified JSON, no line breaks, everything crammed together. It's technically correct. It's also unreadable.

Just Format It

Take that wall of text, paste it into a JSON formatter, and suddenly:

{
  "users": [
    {
      "id": 1,
      "name": "John",
      "email": "john@example.com",
      "settings": {
        "notifications": true,
        "theme": "dark",
        "language": "en"
      }
    }
  ]
}

Same data. Actually readable. You can see the structure, find nested fields, spot missing values.

Common Debugging Scenarios

"The API returns an error but I don't know why"

Format the error response. Often there's a nested message or details field buried in there that explains exactly what went wrong. You just couldn't see it in the minified version.

"I need to compare two responses"

Format both, then use a diff tool. Minified JSON is impossible to diff—everything shows as changed because line breaks are different.

"Is this even valid JSON?"

Paste it into a formatter. If it's invalid, you'll get an error pointing to the problem. Missing comma, extra bracket, unescaped quote—the formatter will tell you.

Working with JWTs

JWTs (JSON Web Tokens) are just base64-encoded JSON. When you see something like:

eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJzdWIiOiIxMjM0NTY3ODkwIiwibmFtZSI6IkpvaG4gRG9lIiwiaWF0IjoxNTE2MjM5MDIyfQ

That's not encrypted. It's just encoded. Decode it and you'll see the actual payload—user ID, expiration time, permissions, whatever the token contains.

Useful for debugging auth issues. "Why am I getting 403?" Decode the token, check if it's expired, verify the claims match what you expect.

Base64 in API Responses

Sometimes APIs return base64-encoded data. File contents, images, encrypted blobs. If you need to see what's actually in there, decode it.

Common in:

• Email APIs (attachments come base64-encoded)
• Image uploads (data URIs are base64)
• Legacy SOAP services (because SOAP)

Tips for API Work

Use browser dev tools. The Network tab shows requests and responses. Most browsers can pretty-print JSON responses automatically.

Save example responses. When an API works correctly, save a formatted copy. When it breaks, you can compare against the working version.

Check the content type. Sometimes what looks like JSON is actually a string containing JSON. You might need to parse it twice.

Watch for encoding issues. Unicode characters can cause problems. If you see \u0000 codes, that's escaped Unicode—usually fine, but sometimes indicates encoding problems upstream.

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API debugging is mostly about seeing the data clearly. Format your JSON, decode your tokens, and you'll spend less time squinting at minified blobs.