# O vs SolidInsight

The clearest difference is rating: SolidInsight at 4.4 against O's 3.8. SolidInsight also leads on review sentiment (100% vs 83%) and update cadence (every 5 weeks vs every 3 months). O's advantage is in-app purchases (none vs 3). On price, ratings volume, ads and device support there is nothing between them.

Both are free to download. SolidInsight sells 3 in-app purchases, starting at $46.99 per year. O asks for nothing beyond the download.

SolidInsight holds the better App Store score, 4.4 against 3.8. Both are backed by a comparable volume of ratings — 5 and 7 respectively. Written reviews point the same way: 83% of O's written reviews are positive against 100% of SolidInsight's.

O ships an update every 3 months, SolidInsight every 5 weeks. The most recent releases landed on September 30, 2026 and September 22, 2026 respectively.

## The numbers

| Metric | O | SolidInsight |
| --- | --- | --- |
| Price | Free | Free |
| Rating | [3.8 (5 ratings)](https://appshunter.io/ios/app/o-ring/id485346224/reviews) | **[4.4 (7 ratings)](https://appshunter.io/ios/app/solidinsight/id1601944650/reviews)** |
| Number of ratings | 5 | **7** |
| Positive reviews | 83.3% of reviews | **100.0% of reviews** |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | Every 3 months | **Every 5 weeks** |
| Monetization | **Free** | Free with in-app purchases |
| Size | 26 MB | 258 MB |
| Requires iOS | **12.1** | 13.0 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 12+ | 4+ |
| Developer | [Trelleborg Sealing Solutions](https://appshunter.io/developer/396863758) | [SHANDONG HOTEAM SOFTWARE CO., LTD.](https://appshunter.io/developer/954963043) |

## What reviewers say

### O

[App page](https://appshunter.io/ios/app/o-ring/id485346224)

This app helps users calculate O-Ring dimensions and find compatible materials for their applications. It provides recommendations based on ISO standards and supports both metric and inch measurements.

**Highlights:** O-Ring housing calculation, O-Ring size recommendations by ISO standard, Quick search by national/international standards, O-Ring tolerance calculation, Metric and inch unit switching, Chemical compatibility check, Integration of Trelleborg Sealing Solutions Videos

**Features:** macOS Compatibility

**In-app purchases:** none


### SolidInsight

[App page](https://appshunter.io/ios/app/solidinsight/id1601944650)

View and collaborate on 2D and 3D CAD files on your mobile device without needing expensive desktop software. Measure designs, access properties, and share feedback instantly.

**Highlights:** Supports major 2D/3D CAD formats, View models and drawings on mobile, Measure design dimensions, Access design properties, Markup and share comments, Isolate/hide components, Browse assembly tree

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

**In-app purchases (3)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Starter Annual Subscription | $46.99 | per year |
| Premium Annual Subscription | $94.99 | per year |
| Unlock features in a design | $0.99 | one-time |


## Frequently asked questions

### Is O free?

O is free to download, with no in-app purchases.

### Is SolidInsight free?

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

### Which has better reviews, O or SolidInsight?

SolidInsight is rated higher. O averages 3.8 out of 5 from 5 ratings, while SolidInsight averages 4.4 from 7 ratings.

### Do O or SolidInsight have ads?

Neither O nor SolidInsight shows ads.

### Which is updated more often, O or SolidInsight?

O ships an update every 3 months, and SolidInsight every 5 weeks. Most recently, O was updated on September 30, 2026 and SolidInsight on September 22, 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.*