Comparison

Strongbox Pro vs S3 Client

Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.

Head to head
About

Strongbox Pro

Securely store and protect all your passwords with one master password. Supports open-source formats and offers advanced security features like biometric unlock, hardware token protection, and cloud syncing.

Highlights
  • Master password protection
  • Biometric unlock (Face ID/Touch ID)
  • Passkey and YubiKey support
  • Military-grade encryption
  • Cloud sync (iCloud, Dropbox, etc.)
  • Password auditing (weak passwords, HIBP check)
  • Secure password generation
Features
Read full description

Strongbox Pro is available here for outright and upfront purchase instead of via an In-App Purchase upgrade. This version of Strongbox is identical to the much loved Strongbox application with all the Pro features and the same regular update schedule. Strongbox is an application for keeping all your passwords safely stored and protected by one master password. Supporting the open source Password Safe and KeePass formats. *** Supports Family Sharing *** *** Features *** - Face ID/Touch ID Unlock for the ultimate in convenience, security and speed. - PIN Code Unlock with a Duress PIN option for those tricky situations. - Passkey support - The latest, most convenient and most secure authentication method (passkeys). - YubiKey protection - secure your databases with a hardware token. - Secure - protected by time tested military grade cryptography. - Private - Isolated In-App attachments viewer for your sensitive documents, photos & videos. - Audit your passwords - Automatically check your database for weak passwords including a 'Have I Been Pwned?' check. - Cloud Support, so you can access your cloud safes using iCloud, Dropbox, OneDrive, Google Drive, WebDAV or SFTP even when offline. Use the built in Files app for many other storage options or store them securely only on your local device. You choose your storage. - Search your entire set of passwords and secrets instantly and powerfully, with deep search. Autocomplete new entries, and auto generate secure passwords. - Compatible - Import/Export by Files app, Email, CSV, iTunes File Sharing or use cloud storage. - Standards compliant - using the time tested Password Safe and KeePass formats so you can import any existing password safe you have. - Features galore - Incredibly configurable password generation including Diceware (XKCD) & regular passwords. - Timed Auto Clear Clipboard. - Entry History. - KeePass Field References, Tags, Custom Icon & FavIcons (including automatic search & download). - Two Factor Authentication codes (TOTP) - QR Code, Steam & Manual. --------------------------------------------------------------------- • Payment will be charged to iTunes Account at confirmation of purchase • Strongbox Privacy Policy may be found here: https://strongboxsafe.com/privacy-policy/ • Strongbox Terms of Use may be found here: https://strongboxsafe.com/terms/

About

S3 Client

Access and manage your S3-compatible cloud storage directly from your device's file system. Files are downloaded on demand and synchronized automatically, with support for various S3 services and encryption methods.

Highlights
  • Direct S3 storage access
  • On-demand file downloading
  • Automatic synchronization
  • Support for multiple S3 services
  • System share sheet uploads
  • Pre-signed sharing link generation
  • Shortcuts automation support
Features
Read full description

Access your S3 storage directly from the Files app, Finder, and other applications on iPhone, iPad, and Mac. Developed by the creator of Working Copy, this application provides seamless integration with S3-compatible storage services. Once configured, S3 buckets appear alongside other cloud storage providers, with files available on demand. Files are downloaded as needed and automatically synchronized back to S3 when modified. The app supports a wide range of S3-compatible services, including AWS S3, BackBlaze B2, CloudFlare R2, DigitalOcean Spaces, MinIO, and others. Files and directories can be uploaded through the system share sheet on iOS and the Services menu on macOS. The app remembers preferred upload destinations for different file types, streamlining file management. Pre-signed sharing links can be generated directly from Finder and the Files app, allowing temporary access to files for up to seven days. Support for server-side encryption with customer-provided keys (SSE-C) and client-side AES-GCM encryption compatible with the Amazon S3 Encryption Client. Comprehensive support for Shortcuts automation enables operations such as listing, downloading, uploading, and moving files. The app is free to use with a single server. A Pro Unlock is required for multiple servers, available as a one-time purchase or a monthly subscription, with access shared across iPhone, iPad, and Mac. A one-week free trial allows users to evaluate Pro features before purchase.

Screenshots

Strongbox Pro4 screens
S3 Client4 screens

Verdict

The call

The clearest difference is price: S3 Client at Free against Strongbox Pro's $99.99. S3 Client also leads on update cadence (every 9 days vs every 2 weeks). Strongbox Pro's advantage is ratings volume (338 vs 54) and device support (5 vs 3). On rating, review sentiment, ads and in-app purchases there is nothing between them.

Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS

CostPrice · In-app purchases · Ads · Monetization

S3 Client is free to download; Strongbox Pro costs $99.99 up front. Strongbox Pro sells 7 in-app purchases, starting at $2.99 per month and S3 Client sells 3 in-app purchases, starting at $2.99 per month. Whichever you choose, the download price is not the number that matters.

ReceptionRating · Positive reviews · Number of ratings

On the App Store both sit at effectively the same score — 4.7 for Strongbox Pro against 4.8 for S3 Client. That said, the two scores are not equally well evidenced: Strongbox Pro has 338 ratings behind it against 54, so its average is the more settled of the two. Written reviews are what separate them: 86% of Strongbox Pro's written reviews are positive against 79% of S3 Client's.

UpkeepUpdate frequency

Strongbox Pro ships an update every 2 weeks, S3 Client every 9 days. The most recent releases landed on September 29, 2026 and September 26, 2026 respectively.

Scorecard6 real differences · 4 level
Strongbox Pro versus S3 Client: the parameters behind the verdict, then further details
ParameterStrongbox ProS3 Client
Price$99.99Free — better
Rating4.7 (338 ratings)4.8 (54 ratings) — better
Positive reviews85.7% of reviews — better79.1% of reviews
Number of ratings338 — better54
Update frequencyEvery 2 weeksEvery 9 days — better
AdsNoNo
In-app purchasesYesYes
MonetizationPaidFree with in-app purchases — better
DevicesiPhone, iPad, iPod, Mac, Apple Watch — betteriPhone, iPad, Mac
Requires iOS15.0 — better18.2
Further details — not scored
Size136 MB63 MB
Age rating4+4+
DeveloperPhoebe Code LimitedAnders Borum ApS

Customer experience

Strongbox Pro

All ratings338 ratings
Positive93.5%
Neutral0.9%
Negative5.6%
Written reviews223 reviews
Positive85.7%
Neutral3.6%
Negative10.8%

S3 Client

All ratings54 ratings
Positive94.4%
Neutral1.9%
Negative3.7%
Written reviews86 reviews
Positive79.1%
Neutral10.5%
Negative10.5%

Bugs and requests

Strongbox Pro

Not enough reviews yet to summarise bugs or requests.

S3 Client

Reported bugs

17 issues
  • Files renamed randomly
  • High CPU usage
  • Stopped working in iOS 26
  • Can't set permissions
  • Fails to load S3 buckets properly
Show 12 more
  • Duplicating root folders
  • Folders missing
  • Failing to upload
  • No image/video thumbnails
  • EXIF option unreliable
  • No SSE-C encryption/decryption support
  • Does not support IAM policy roles
  • Short-lived keys needed
  • App locks up Files app
  • Requires reboot
  • Issues with S3 Minio
  • Update issues with older macOS

Requested features

14 requests
  • Support for WebDAV servers
  • Support for Google OAuth for GCS
  • Synchronous feature to backup photos automatically
  • Configurable AWS endpoint for non-.com endpoints
  • Allow import/export of configuration
Show 9 more
  • Show number of files in a directory
  • Option to clear app cache
  • Support for SSE-C encryption/decryption
  • Support for IAM policy roles
  • Support for S3 buckets with short-lived keys
  • Dark mode option
  • Advanced analytics dashboard
  • Duplicate Settings option for iOS
  • Support for public dataset anonymous configuration

In-app purchases

7 purchases

Strongbox Pro

Subscriptions2
  • Monthly Tip$2.991 Month
  • Annual Tip$19.991 Year
One-time5
  • Little Tip$4.99
  • Small Tip$9.99
  • Medium Tip$19.99
Show 2 more
  • Large Tip$99.99
  • Huge Tip$199.99
3 purchases

S3 Client

Subscriptions1
  • S3 Files Pro Monthly7 Days trial$2.991 Month
One-time2
  • Lifetime S3 Pro$14.99
  • Lifetime S3 Pro$17.99

Questions

Is Strongbox Pro free?
Strongbox Pro costs $99.99, and also offers in-app purchases.
Is S3 Client free?
S3 Client is free to download, with in-app purchases available.
Which has better reviews, Strongbox Pro or S3 Client?
S3 Client is rated higher. Strongbox Pro averages 4.7 out of 5 from 338 ratings, while S3 Client averages 4.8 from 54 ratings.
Do Strongbox Pro or S3 Client have ads?
Neither Strongbox Pro nor S3 Client shows ads.
Which is updated more often, Strongbox Pro or S3 Client?
Strongbox Pro ships an update every 2 weeks, and S3 Client every 9 days. Most recently, Strongbox Pro was updated on September 29, 2026 and S3 Client on September 26, 2026.

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