Open & Free

Developer Tools & Public APIs

Utilities built for developers. Free to use, no sign-up, no rate-limit surprises.

3Public Tools

FreeNo API Key

<50msResponse Time

99.9%Uptime

Available Now

Tools & Endpoints

CLIENT-SIDEjson-viewer.symelo.com

JSON Viewer

Operational

Paste or load any JSON document. Syntax highlighted, collapsible tree, search and filter, copy path.

Syntax highlighting
Collapse/expand nodes
Search & filter keys
Copy JSON path

// Paste JSON in the input box
// or load from a URL
{
  "status": "ok",
  "data": { "id": 1, "name": "..." }
}

POSTapi.symelo.com/v1/repair

JSON Repair API

Operational

Send malformed JSON, get back valid JSON. Handles trailing commas, missing quotes, and truncated payloads.

No auth required
Truncated payload handling
Trailing commas & bare keys
1,000 req/day free tier

fetch('https://api.symelo.com/v1/repair', {
  method: 'POST',
  headers: { 'Content-Type': 'application/json' },
  body: JSON.stringify({ input: '{broken: json,' })
})
.then(r => r.json())
.then(d => console.log(d.result));

CLIENT-SIDEb64.symelo.com

Base64 Toolkit

Operational

Encode and decode strings, files, and images. Generates Data-URLs for inline use. Nothing leaves your browser.

Encode/decode strings
File & image support
Data-URL output
100% client-side

// In your browser console:
btoa('Hello, Symelo!')
// → 'SGVsbG8sIFN5bWVsbyE='
 
atob('SGVsbG8sIFN5bWVsbyE=')
// → 'Hello, Symelo!'

Fair Use Policy

Rate Limits

Endpoint	Free Tier	Max Payload	Auth Required	SLA
json-viewer.symelo.com	Unlimited	N/A (client)	No	99.9%
api.symelo.com/v1/repair	1,000 req/day	50 KB	No	99.9%
b64.symelo.com	Unlimited	N/A (client)	No	99.9%