# Authenticator 2FA by KeepSolid vs Duo Authenticator

The clearest difference is in-app purchases: Authenticator 2FA by KeepSolid at none against Duo Authenticator's 3. Authenticator 2FA by KeepSolid also leads on ads (none vs shown) and review sentiment (75% vs 50%). Duo Authenticator's advantage is rating (4.2 vs 3.9). On price, ratings volume and update cadence there is nothing between them.

Both are free to download. Duo Authenticator sells 3 in-app purchases, starting at $3.99 per 7 days. Authenticator 2FA by KeepSolid asks for nothing beyond the download.

Duo Authenticator holds the better App Store score, 4.2 against 3.9. Both are backed by a comparable volume of ratings — 11 and 24 respectively. Written reviews complicate that: 75% of Authenticator 2FA by KeepSolid's written reviews are positive against 50% of Duo Authenticator's, so the app with the better star average is not the one people write more warmly about.

Both ship on a similar rhythm, roughly monthly. The most recent releases landed on October 24, 2026 and October 25, 2026 respectively.

## The numbers

| Metric | Authenticator 2FA by KeepSolid | Duo Authenticator |
| --- | --- | --- |
| Price | Free | Free |
| Rating | [3.9 (11 ratings)](https://appshunter.io/ios/app/authenticator-2fa-by-keepsolid/id1660779042/reviews) | **[4.2 (24 ratings)](https://appshunter.io/ios/app/duo-authenticator/id1665454984/reviews)** |
| Number of ratings | 11 | **24** |
| Positive reviews | **75.0% of reviews** | 50.0% of reviews |
| In-app purchases | **No** | Yes |
| Ads | **No** | Yes |
| Update frequency | Monthly | Monthly |
| Monetization | **Ad-supported** | Free with in-app purchases |
| Size | 45 MB | 61 MB |
| Requires iOS | **14.0** | 16.6 |
| Devices | **iPhone, iPad, iPod, Apple Watch** | iPhone |
| Age rating | 4+ | 4+ |
| Developer | [KeepSolid Inc.](https://appshunter.io/developer/674978021) | [Petr Polasek](https://appshunter.io/developer/1613323784) |

## What reviewers say

### Authenticator 2FA by KeepSolid

[App page](https://appshunter.io/ios/app/authenticator-2fa-by-keepsolid/id1660779042)

This app generates time-based one-time passwords to add an extra layer of security for your online accounts. It supports multi-factor authentication for services like Facebook, Google, and Amazon, protecting your data from unauthorized access. The app offers multi-device support and a user-friendly interface.

**Highlights:** Two-factor authentication (TFA/2FA), Time-based one-time passwords (TOTP), Multi-device support, Secure code generation, User-friendly interface, Account aggregation

**Features:** Apple Watch app, Vision Pro support

**In-app purchases:** none


### Duo Authenticator

[App page](https://appshunter.io/ios/app/duo-authenticator/id1665454984)

Enhance your online security with this multi-factor authentication app. It provides an extra layer of protection for your accounts by generating time-sensitive codes, even when offline. Secure your sensitive information with ease and peace of mind.

**Highlights:** Quick and easy setup, Wide service compatibility, Time-sensitive security codes, Offline code generation, End-to-end encryption, Security code protection

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

**In-app purchases (3)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Premium 1 Week | $3.99 | per 7 days |
| Premium 1 Month | $9.99 | per month |
| Premium 1 Year | $29.99 | per year |


## Frequently asked questions

### Is Authenticator 2FA by KeepSolid free?

Authenticator 2FA by KeepSolid is free to download, with no in-app purchases.

### Is Duo Authenticator free?

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

### Which has better reviews, Authenticator 2FA by KeepSolid or Duo Authenticator?

Duo Authenticator is rated higher. Authenticator 2FA by KeepSolid averages 3.9 out of 5 from 11 ratings, while Duo Authenticator averages 4.2 from 24 ratings.

### Do Authenticator 2FA by KeepSolid or Duo Authenticator have ads?

Duo Authenticator shows ads; Authenticator 2FA by KeepSolid does not.

### Which is updated more often, Authenticator 2FA by KeepSolid or Duo Authenticator?

Authenticator 2FA by KeepSolid ships an update monthly, and Duo Authenticator monthly. Most recently, Authenticator 2FA by KeepSolid was updated on October 24, 2026 and Duo Authenticator on October 25, 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.*