Apier – REST API Tester & HTTP Client by Leepverse

Apier – Built Light. Runs Fast.

A lightweight API client for developers. Test HTTP, GraphQL, and SOAP APIs, connect to WebSocket and Socket.IO servers, generate cURL commands, organize collections, manage variables, simulate network conditions, install official extensions, and debug APIs directly in your browser.

Apier is built for developers who want a fast, clean, and privacy-focused API client without installing heavy desktop applications.

What is Apier?

Apier is a modern API testing and debugging tool that lets you work with HTTP, GraphQL, SOAP, WebSocket, and Socket.IO from one lightweight workspace.

Everything runs locally in your browser—no accounts, no cloud sync, and no unnecessary complexity.

Features

• HTTP API Testing
- GET, POST, PUT, PATCH, DELETE, HEAD, OPTIONS
- Query Parameters
- Request Headers
- Cookies
- JSON, XML, Text & Form Data
- File Upload (Multipart)
- Request Body Editor
- Request Cancellation

• GraphQL
- GraphQL Queries
- Variables Support
- Custom Headers
- Response Viewer

• SOAP
- SOAP Request Editor
- XML Request Body
- SOAPAction Header Support
- Custom Headers
- XML Response Viewer

• WebSocket & Socket.IO
- WebSocket Client
- Socket.IO Client
- Send & Receive Messages
- Real-time Event Logs

• Response Tools
- Pretty View
- Raw View
- Tree View
- Response Headers
- JSON Export
- XML Export
- TXT Export
- Multi-language Code Generation
- Response Size
- Response Time
- HTTP Status

• Organization
- Collections
- Nested Folders
- Saved Requests
- Request History
- Search & Reuse Requests

• Variables
- Global Variables
- Variable Collections
- Dynamic Variable Replacement
- Reusable Environments

• Developer Tools
- cURL Generator
- Auto Runner
- Request Repetition
- Configurable Delay
- Network Latency Simulation
- Offline Mode

• Extensions
- Official Extension Marketplace
- Install Official Extensions
- Enable or Disable Extensions
- Built-in Productivity Tools
- Expand Apier Functionality

• Personalization
- Multiple Themes
- Avatar Selection
- Light & Dark Mode
- Modern Interface

Privacy

Apier is privacy-first.

• No account required
• No cloud storage
• No tracking
• No analytics
• No personal data collection
• All requests, collections, variables, history, settings, and extensions remain on your device

Use Cases

• Test HTTP APIs
• Test GraphQL APIs
• Test SOAP Services
• Debug Backend Services
• Connect to WebSocket Servers
• Test Socket.IO Applications
• Generate cURL Commands
• Export API Responses
• Organize API Collections
• Simulate Network Conditions
• Extend Apier with Official Extensions
• Learn API Development

Whether you're building APIs, debugging backend services, integrating third-party services, or learning web development, Apier provides a fast, lightweight, and developer-friendly workspace for everyday API testing across HTTP, GraphQL, SOAP, WebSocket, and Socket.IO.