Format, validate and explore JSON
Beautify or minify JSON, pinpoint syntax errors, explore nested objects in a tree and copy the full path of any key. Open JSON Playground →
Local-first developer toolkit
Small tools for
serious development.
Format data, inspect requests, mock APIs, expose localhost and write technical documentation—without breaking your flow.
- Browser based
- Privacy first
- Free to use
Your toolbox
Choose a tool.
Keep your momentum.
Focused utilities that work together as one developer workspace. Open one and get straight to the task.
₹
Payment simulation
Popular
LM Pay
Simulate payment gateways with UPI, cards, netbanking, custom scenarios, API credentials, and webhooks.
- Gateway profiles
- Payment scenarios
- Webhook delivery
D/
Write & preview
Documentation Studio
Open, edit, preview, and safely save Markdown or HTML documents with an instant split-screen workflow.
- Live preview
- Markdown & HTML
- Local-first editing
OAS
API documentation
OpenAPI / Swagger Preview
Edit OpenAPI or Swagger JSON and YAML beside searchable, interactive API reference documentation.
- OpenAPI 3.x
- Swagger 2.0
- JSON & YAML
⌁
API development
API Mocker
Create realistic mock endpoints with custom responses, headers, status codes, latency, collections, and request inspection.
- Custom responses
- Request history
- Collections
{ }
Data utilities
JSON Playground
Format, inspect, search, and navigate JSON with a highlighted editor and an interactive tree view.
- Format & minify
- Tree view
- Key path finder
⇄
Webhook debugging
Webhook Inbox
Capture webhook deliveries, inspect headers and payloads, then replay the exact request to a public endpoint or your own tunnel.
- Live capture
- Request inspector
- Safe replay
↗
Private ingress
Secure Tunnels
Expose a local HTTP service through a stable HTTPS subdomain using Python, Docker, Podman, or the Bash launcher.
- Stable subdomains
- HTTPS ingress
- Multiple agents
One connected workflow
From incoming request
to working response.
Localmachine connects the repetitive parts of API development. Capture real payloads, inspect their structure, replay them locally and turn them into reliable mocks.
Explore Webhook Inbox- 01Capture
Receive a webhook at a secure public endpoint.
- 02Inspect
Read headers, JSON payloads and request history.
- 03Replay
Forward the exact request to a tunnel or custom URL.
- 04Mock
Turn a successful response into a reusable endpoint.
Built for focused development
Developer tools that stay close to your workflow
Localmachine brings common development tasks into one browser-based workspace, without forcing every job into a large platform.
Capture and replay webhooks
Receive webhook deliveries at a public URL, inspect headers and payloads, then replay the exact request to your development endpoint. Open Webhook Inbox →
Create mock API endpoints
Define REST endpoints with custom JSON, headers, status codes and latency, then inspect every captured request. Create a mock API →
Expose localhost through HTTPS
Give a local application a stable public address for webhook testing, demos and cross-device development. Create a secure tunnel →
Write technical documentation
Edit Markdown or HTML with live previews for Mermaid, mathematics, highlighted code and rich technical content. Open Documentation Studio →
Localmachine questions
What is Localmachine?
Localmachine is a collection of focused developer tools for JSON inspection, webhook capture and replay, API mocking, localhost tunneling and technical documentation.
Are the tools free?
The current tools can be opened without a paid subscription. Some features use accounts to retain data or reserve tunnel names.
Does Localmachine upload my JSON?
No. JSON formatting, validation, highlighting and tree generation run directly in your browser.
Ready when you are