# OnePreview: File Viewer — Markdown, Code, JSON & ZIP

> Developer file previewer for Markdown, code, databases, and archives on iOS. (iPhone/iPad app by 培克 罗.)

- Source: https://appshunter.io/ios/app/onepreview-file-viewer/id6760284919 (this page in markdown: same URL + `.md`)
- Developer: [培克 罗](https://appshunter.io/developer/1516557687)
- Category: Productivity, Utilities
- Price: Free
- Rating: 5.00/5 from 1 App Store ratings · 3 written reviews indexed
- Age rating: 4+
- Requires: iOS 17.0 · 9 MB
- Languages: Chinese (Simplified, China), Russian, Hindi, Indonesian, German (Germany), Japanese, French (France), Chinese (Traditional, Taiwan), American English, Mexican Spanish and 1 more
- Released: 2026-03-25
- Data updated: 2026-10-18
- Monetization: free
- User reviews in markdown: https://appshunter.io/ios/app/onepreview-file-viewer/id6760284919/reviews.md

## What is OnePreview?

Preview Markdown, source code, structured data and archives on iPhone and iPad. OnePreview is a local-first file viewer with no account required.

READ MARKDOWN, DIAGRAMS AND MATH
View GitHub-style Markdown with tables, task lists and highlighted code. Switch between rendered content and source. Mermaid diagrams and KaTeX formulas use bundled rendering assets.

EXPORT MARKDOWN TO PDF
Open a standard Markdown file (.md or .markdown) in OnePreview to create an A4 PDF report. Check the actual PDF preview, with continued table headers, wrapped code, Mermaid diagrams and KaTeX formulas, then save it using the system file interface. Document content is processed on your device.

INSPECT DATA, CODE AND ARCHIVES
Read structured data and source code, inspect SQLite schemas and sample rows without editing the database, and see the folder hierarchy inside ZIP and TAR.GZ archives before extracting.

SUPPORTED FORMATS
Markdown (.md, .markdown), MDX, TextBundle, TextPack, JSON, JSONL, YAML, XML, CSV, TSV, TOML, ENV, INI, properties, Apple property lists (plist), SQLite (.sqlite, .sqlite3, .db), source code, plain text, logs, ZIP, TAR.GZ and TGZ. Syntax highlighting supports languages including Swift, Python, JavaScript, TypeScript, Java, C/C++, Objective-C, Ruby, Rust and Shell.

OPEN YOUR FILES
Tap Open File in OnePreview, or long-press a supported document in Files, choose Open With, then select OnePreview. A normal tap in Files may use Apple's built-in preview; OnePreview does not replace every system preview on iPhone or iPad. Try the sample folder from the home screen to explore supported formats.

## Key features

- Markdown and MDX rendering
- JSON, YAML, XML, CSV, TSV, TOML, ENV parsing
- SQLite database inspection
- Source code and log viewing
- ZIP and TAR.GZ archive content preview
- Mermaid diagrams and KaTeX math rendering
- A4 PDF export for Markdown files

## Is OnePreview safe?

Not enough ratings yet to assess OnePreview.

## Is OnePreview legit?

OnePreview: File Viewer appears legitimate, with a few gaps. The AppsHunter Legitimacy Score for OnePreview is 70 out of 100 points across 7 verification signals from App Store and developer data.

## Recent user reviews (3 of 3)

All indexed reviews: https://appshunter.io/ios/app/onepreview-file-viewer/id6760284919/reviews.md

### 5/5 — Useful!

*2026-10-06*

I use OnePreview for quickly checking files.

Update — October 6, 2026
My previous requests have been addressed in version 1.4.2. Thank you!

1. Files can now be opened directly from OnePreview.
2. Switching views and scrolling through longer files is now much smoother and more stable.

**Developer response:** Hi, thanks for the thoughtful suggestions. OnePreview 1.4.2 is now available with an **Open File** button for previewing files directly in the app. We’ve also improved switching to and scrolling through Raw Text in longer files. We appreciate you helping us make OnePreview better!

### 5/5 — 意外发现了这款软件

*2026-09-07*

和 codex 的对话记录打不开，stroe 推荐了这个软件，实测能打开

**Developer response:** 感谢支持！很高兴 OnePreview 帮你顺利打开了 Codex 的对话记录。我们会继续完善格式兼容和预览体验，有问题欢迎随时反馈。

### 5/5 — 不错的软件，比那些收费的好用多了

*2026-06-04*

文件预览很方便，格式支持多，用起来挺顺手

**Developer response:** 感谢认可！很高兴 OnePreview 能让文件预览更方便、更顺手。我们会继续优化体验，并支持更多实用格式。

## Frequently asked questions about OnePreview

### What file types can OnePreview preview?

OnePreview supports a wide range of file types including GitHub-style Markdown, MDX, TextBundle, TextPack, JSON, JSONL, YAML, XML, CSV, TSV, TOML, ENV, SQLite databases, source code, plain text, logs, and ZIP/TAR.GZ archives.

### Does OnePreview require an account?

No, OnePreview is designed for local-first processing and does not require an account to use its features. This ensures your data remains private and processing is fast.

### Can I export my Markdown files from OnePreview?

Yes, you can export standard Markdown files as A4 PDF reports. This feature allows you to preview rendered content, including table headers, wrapped code, Mermaid diagrams, and KaTeX formulas, before saving the PDF.

### How does OnePreview handle structured data?

OnePreview allows you to inspect structured data formats like JSON, YAML, and XML, as well as view SQLite database schemas. This makes it easier to understand and work with complex data directly on your device.

### Is OnePreview available on Mac?

Yes, OnePreview is supported on Mac, iPhone, and iPad, allowing for a consistent file previewing experience across Apple devices.

### How often is OnePreview updated?

The latest version of OnePreview, 1.4.4, was released on October 10, 2026. Updates are provided to ensure compatibility and introduce new features or improvements.

### What is the age rating for OnePreview?

OnePreview has an age rating of 4+, making it suitable for a wide range of users, including younger individuals who may be exploring developer-related content.

### Does OnePreview have ads?

No, OnePreview is ad-free. As a free application, it does not contain advertisements, providing an uninterrupted user experience.

## Version history (last 5 releases)

### 1.4.5 — 2026-10-16

1. A refreshed interface with dedicated Files, Settings, and Help pages.
2. Improved folder and SQLite previews, reliability, and Markdown PDF export.

### 1.4.4 — 2026-10-10

1. Added Spanish (Mexico) localization.
2. Improved preview performance and compatibility for Markdown and other text files.

### 1.4.3 — 2026-10-09

1. Export Markdown as an A4 PDF report, with tables, diagrams and formulas.
2. Improved pagination for long tables, code and text.

### 1.4.2 — 2026-10-05

1. Open files directly in OnePreview from the new Open File button.
2. Smoother Raw Text switching and scrolling for longer files.

### 1.4.1 — 2026-09-07

Clarifies how to open supported files from Files on iPhone and iPad.

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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 2026-10-18.*