# JSON Master vs OLM Converter · Viewer, Reader

The clearest difference is review sentiment: JSON Master at 100% against OLM Converter · Viewer, Reader's 0%. OLM Converter · Viewer, Reader's advantage is ads (none vs shown). On price, update cadence, in-app purchases and monetization model there is nothing between them.

Both are free to download. JSON Master sells 3 in-app purchases, starting at $2.99 per 7 days and OLM Converter · Viewer, Reader sells 3 in-app purchases, starting at $4.99 per 7 days. Whichever you choose, the download price is not the number that matters.

JSON Master ships an update every 9 days, OLM Converter · Viewer, Reader every 5 days. The most recent releases landed on October 3, 2026 and October 5, 2026 respectively.

## The numbers

| Metric | JSON Master | OLM Converter · Viewer, Reader |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[4.6 (5 ratings)](https://appshunter.io/ios/app/json-master-editor-and-viewer/id6757484875/reviews)** | — |
| Number of ratings | **5** | — |
| Positive reviews | **100.0% of reviews** | 0.0% of reviews |
| In-app purchases | Yes | Yes |
| Ads | Yes | **No** |
| Update frequency | Every 9 days | **Every 5 days** |
| Monetization | Free with in-app purchases | Free with in-app purchases |
| Size | 41 MB | 24 MB |
| Requires iOS | 15.0 | 15.0 |
| Devices | iPhone, iPad, iPod | **iPhone, iPad, iPod, Mac** |
| Age rating | 4+ | 4+ |
| Developer | [Tianjin Illuso Information Technology Co., Ltd.](https://appshunter.io/developer/1864792206) | [Rush Tools LLC](https://appshunter.io/developer/1896773547) |

## What reviewers say

### JSON Master

[App page](https://appshunter.io/ios/app/json-master-editor-and-viewer/id6757484875)

This offline iOS tool formats, views, validates, and converts JSON data. It supports large files and offers privacy-safe, local processing for developers needing to debug API responses or transform data formats.

**Highlights:** Offline JSON formatting and beautifying, Tree and text view for JSON visualization, Instant JSON syntax validation, JSON to CSV, XML, Excel conversion, Large file support, Import from clipboard and files

**Features:** macOS Compatibility, Vision Pro support

**In-app purchases (3)**

| Purchase | Price | Billing |
| --- | --- | --- |
| JSON Master Pro (Weekly) | $2.99 | per 7 days |
| Pro (Yearly) | $14.99 | per year |
| JSON Master Pro Lifetime | $17.99 | one-time |


### OLM Converter · Viewer, Reader

[App page](https://appshunter.io/ios/app/olm-converter-viewer-reader/id6781821148)

Easily open, read, and convert Outlook for Mac archive files (.olm) on your devices. Browse mail, contacts, calendars, and tasks, then export them to various formats like MBOX, PDF, and CSV without needing Outlook.

**Highlights:** Open .olm archives without Outlook, Read mail, contacts, calendar, notes, tasks, Browse full folder tree, Search mail by subject, sender, text, Convert to MBOX, EML, PDF, CSV, HTML, vCard, ICS, Export entire mailboxes or selected folders, Works offline on device

**Features:** Vision Pro support

**In-app purchases (3)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Pro Weekly | $4.99 | per 7 days |
| Pro Annual | $39.99 | per year |
| Pro Lifetime | $59.99 | one-time |


## Frequently asked questions

### Is JSON Master free?

JSON Master is free to download, with in-app purchases available.

### Is OLM Converter · Viewer, Reader free?

OLM Converter · Viewer, Reader is free to download, with in-app purchases available.

### Do JSON Master or OLM Converter · Viewer, Reader have ads?

JSON Master shows ads; OLM Converter · Viewer, Reader does not.

### Which is updated more often, JSON Master or OLM Converter · Viewer, Reader?

JSON Master ships an update every 9 days, and OLM Converter · Viewer, Reader every 5 days. Most recently, JSON Master was updated on October 3, 2026 and OLM Converter · Viewer, Reader on October 5, 2026.

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*Compared by [AppsHunter](https://appshunter.io/) from daily US App Store data. Review summaries are generated from verbatim App Store reviews.*