# PJConverter — Projection Convert Tool

> Professional coordinate transformation tool for GIS, surveying, and engineering. (iPhone/iPad app by Zhikang Qin.)

- Source: https://appshunter.io/ios/app/pjconverter/id1123601167 (this page in markdown: same URL + `.md`)
- Developer: [Zhikang Qin](https://appshunter.io/developer/1123601166)
- Category: Utilities, Productivity
- Price: $0.99
- Age rating: 4+
- Requires: iOS 17.0 · 6 MB
- Languages: American English, Chinese (Simplified, China)
- Released: 2016-06-16
- Data updated: 2026-09-24
- Monetization: paid
- User reviews in markdown: https://appshunter.io/ios/app/pjconverter/id1123601167/reviews.md

## What is PJConverter?

PJ Converter is the ultimate coordinate conversion tool designed for professionals and students in Geographic Information Systems (GIS), surveying, engineering, and related fields. Whether 
you're working with geodetic or projected coordinates, it delivers unparalleled accuracy and ease of use.

Key Features
  * Professional-Grade Conversion Engine: Powered by the widely-used PROJ library to ensure every calculation is accurate and reliable. It supports forward, inverse, and full coordinate 
    transformation pipelines to meet the most demanding professional needs.
  * Vast Coordinate System Library: Comes with thousands of built-in Coordinate Reference Systems (CRS) from authoritative sources like EPSG, covering the entire globe. The powerful search 
    helps you find what you need in seconds.
  * Advanced Custom Projections: Need something specific? Easily create, edit, and manage your own projection definitions. The editor provides real-time syntax validation and ID conflict 
    detection to make complex configurations foolproof.
  * Visual Projection Preview: Instantly generate a world map preview for any coordinate system. Visually assess a projection's distortion, area of use, and characteristics before you apply it. 
    No more guesswork.
  * Flexible Formatting: Seamlessly switch between degrees (DMS) and radians for geographic coordinates. Pick coordinates visually from an integrated map to meet diverse data input and display 
    requirements.
  * Simple & Efficient Experience: The "Recents" list automatically saves your frequently used projections for quick access. The entire interface is clean and focused, letting you perform 
    conversions without distraction.

PJ Converter is the ideal choice for field engineers, GIS analysts, geography students, and anyone who works with spatial data.
Download now and make complex coordinate conversions simpler and more efficient than ever before.

## Key features

- Professional-grade conversion engine
- Extensive library of coordinate systems
- Customizable projection creation
- Visual projection previews
- Flexible format support
- Intuitive user interface

## Recent user reviews (2 of 2)

All indexed reviews: https://appshunter.io/ios/app/pjconverter/id1123601167/reviews.md

### 1/5 — 没任何客服联系方式

*2016-11-10*

经纬度定完转80坐标系，跟手持完全搭不上边

### 4/5 — 坐标

*2016-06-19*

怎么没有指导用

## Frequently asked questions about PJConverter

### What is 投影转换器 used for?

投影转换器 is a professional tool designed for precise coordinate transformations, essential for Geographic Information Science (GIS), surveying, and engineering tasks. It handles both geographic and projected coordinates with high accuracy.

### How accurate is 投影转换器?

The app utilizes the industry-standard PROJ library, ensuring every conversion is accurate and reliable. It supports forward, inverse, and complete coordinate transformation processes to meet stringent professional requirements.

### Does 投影转换器 support many coordinate systems?

Yes, 投影转换器 includes thousands of coordinate reference systems (CRS) from authoritative sources like EPSG, covering global data. A powerful search function helps you quickly find the specific CRS you need.

### Can I create my own coordinate systems in 投影转换器?

Absolutely. The app allows you to easily create, edit, and manage your own projection parameters. It features real-time syntax checking and ID conflict detection for a seamless customization experience.

### Is 投影转换器 suitable for beginners?

While designed for professionals, 投影转换器 offers a concise and efficient experience. The visual projection preview feature helps users intuitively understand projections, making it more accessible.

### What devices does 投影转换器 support?

投影转换器 is available for iPhone and iPad, providing a consistent experience across Apple's mobile platforms.

### How often is 投影转换器 updated?

The app was last updated on October 7, 2025, indicating ongoing development and support. The latest version is 3.0.

### Does 投影转换器 have ads?

No, 投影转换器 is ad-free, providing an uninterrupted user experience for its paid users.

## Version history (last 5 releases)

### 3.0 — 2025-10-07

This is a milestone update. PJ Converter has been rebuilt from the ground up using the latest SwiftUI technology, delivering a faster, more powerful, and more modern professional tool.

Here's what's new in this major update:
  * [A FRESH NEW LOOK] Completely Redesigned UI
      * The app has been rewritten entirely. It's faster, more responsive, and features a modern design with fluid animations.
      * Native Dark Mode: Perfectly integrated with iOS Dark Mode for a more comfortable viewing experience in low-light conditions.
  * [MAJOR FEATURE LEAP] More Powerful Conversions
      * Degree/Radian Switching: Seamlessly switch geographic coordinates between degrees (DMS) and radians to meet diverse data requirements.
      * Upgraded Map Picker: The map picker can now directly return values in degrees for a more intuitive workflow.
  * [SMARTER MANAGEMENT] A More Professional Projection Library
      * Real-Time Validation: The custom projection editor now validates your parameters in real-time and warns of potential ID conflicts, making configuration safer.
      * Recents: Your most frequently used coordinate systems now automatically appear at the top of the list for quick access.
  * [REWRITTEN CORE] A More Stable Foundation
    We've overhauled the data layer for faster and more reliable access to your custom and recent projections. We've also introduced new observability tools, which will help us find and fix 
issues even faster in the future.

We believe this upgrade will lead to a more efficient and enjoyable workflow. We hope you enjoy it.

### 2.3 — 2021-02-15

Adapt to iOS 14 and fix some bugs.

### 2.2 — 2017-10-07

适配了iOS 11和iPhone X。

### 2.1 — 2017-02-15

添加了投影预览功能，你可以预览任意投影下的世界地图轮廓。
你可以去投影参数查询页面点击“预览”来体验！

### 2.0 — 2017-01-10

重新设计了全部UI，逻辑更加清晰，界面更加优雅，操作更加流畅，增强了稳定性。

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## More apps by Zhikang Qin

- [CycleTask — Rituals on Repeat](https://appshunter.io/ios/app/cycletask-rituals-on-repeat/id6752910735)

All apps by Zhikang Qin: https://appshunter.io/developer/1123601166

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*Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-09-24.*