PGP Software Comparison: Which Encryption Tool Is Right for You?

How do PGP tools compare? The answer depends on what you need. Some PGP software prioritizes command-line power and protocol compliance, while others focus on graphical interfaces and ease of use. In this comprehensive PGP software comparison, we evaluate seven of the most widely used PGP encryption tools across security, usability, platform support, and price. Whether you are a developer managing signing keys, a journalist protecting sources, or an everyday user who wants private communication, this guide will help you find the right tool. We cover KeychainPGP, GnuPG, Gpg4win, GPG Suite, Mailvelope, OpenKeychain, and Proton Mail so you can make an informed decision.

Comparison Criteria

Before diving into the detailed PGP tools comparison, it helps to understand the criteria that matter most when choosing encryption software. Not every user weighs these factors equally, but each one can be decisive depending on your threat model and workflow.

• Security and cryptographic foundation. The underlying crypto library determines algorithm support, vulnerability surface, and long-term maintainability. Tools built on well-audited, memory-safe libraries have an inherent advantage over those relying on decades-old C codebases.
• Ease of use. A tool that is too difficult to use correctly is a tool that will be used incorrectly — or not at all. Setup time, learning curve, and the path to a first successful encryption or signature all matter.
• Platform support. Some users live entirely in a browser; others need native desktop performance. Mobile support is increasingly important for on-the-go decryption.
• Algorithm and key type support. Modern elliptic-curve keys (Ed25519, X25519, NIST P-256/P-384) offer stronger security at smaller key sizes compared to legacy RSA. Not every tool supports them equally.
• Key management. How a tool generates, stores, imports, exports, and backs up keys directly affects both security and convenience.
• Open source status. Open-source software allows independent auditing and community review. Proprietary or partially open tools require more trust in the vendor.
• Price. Some tools are completely free; others use freemium models or require a subscription for full functionality.

Understanding these criteria will help you interpret the comparison tables and detailed analyses that follow.

Feature Comparison Table

The table below provides a high-level snapshot of how these PGP encryption tools compare on core features. For a deeper look at each tool, see the detailed analysis section.

Tool	Type	Platforms	Key Types	Open Source	GUI	CLI	Web	Mobile	Price
KeychainPGP	Desktop / Mobile / Web / CLI	Windows, macOS, Linux, Android, Web	Ed25519, X25519, RSA, NIST P	Yes	Yes	Yes	Yes	Yes	Free
GnuPG	CLI tool	Linux, macOS, Windows	RSA, DSA, ElGamal, Ed25519, Cv25519, NIST P	Yes (GPLv3)	No	Yes	No	No	Free
Gpg4win	Desktop suite	Windows	Same as GnuPG	Yes (GPLv2+)	Yes (Kleopatra)	Yes (via GnuPG)	No	No	Free
GPG Suite	Desktop suite	macOS	Same as GnuPG	Partially	Yes (GPG Keychain)	Yes (via GnuPG)	No	No	Freemium
Mailvelope	Browser extension	Chrome, Firefox, Edge	RSA, ECC (via OpenPGP.js)	Yes (AGPLv3)	Yes	No	Partial	No	Free
OpenKeychain	Mobile app	Android	RSA, ECC (via Bouncy Castle)	Yes (GPLv3)	Yes	No	No	Yes	Free
Proton Mail	Email service	All (browser), iOS, Android	RSA, X25519	Partially (clients)	Yes	No	Yes	Yes	Freemium

This feature comparison table gives you the broad strokes. The sections that follow break down each dimension in greater detail.

Security Comparison

Security is the primary reason people use PGP in the first place, so the cryptographic underpinnings of each tool deserve close examination. Here is how the major PGP software compares on security-relevant characteristics.

Cryptographic Libraries

• KeychainPGP is built with Rust and Sequoia-PGP, a modern OpenPGP implementation written in a memory-safe language. Memory-safety eliminates entire classes of vulnerabilities (buffer overflows, use-after-free) that have historically plagued C-based implementations. Sequoia has been independently audited and is actively maintained.
• GnuPG uses its own C-based libgcrypt library. While battle-tested over two decades, C code is inherently more susceptible to memory corruption bugs. GnuPG has had multiple CVEs related to memory handling.
• Gpg4win and GPG Suite both wrap GnuPG and inherit its library, security profile, and any vulnerabilities.
• Mailvelope uses OpenPGP.js, a JavaScript implementation. While memory-safe by virtue of running in a managed runtime, JavaScript introduces its own concerns around timing side-channels and browser sandbox escapes.
• OpenKeychain relies on Bouncy Castle, a widely used Java cryptographic library with a solid track record.
• Proton Mail uses OpenPGP.js on the web and GopenPGP (Go) in native apps. Both are memory-safe implementations.

Audit Status

KeychainPGP benefits from Sequoia-PGP’s independent security audit. GnuPG has undergone audits funded by various organizations, including the Linux Foundation’s Core Infrastructure Initiative. Proton Mail has published audit reports for its client applications. Mailvelope and OpenKeychain have had community review but fewer formal audits.

Key Storage

• KeychainPGP stores private keys in the OS credential manager (Windows Credential Manager, macOS Keychain, or Linux Secret Service) backed by a SQLite keyring. The optional OPSEC mode switches to RAM-only key storage and wipes sensitive data from memory after use.
• GnuPG stores keys in ~/.gnupg/ on disk, protected by the GPG agent and a passphrase.
• Mailvelope stores keys in the browser’s local storage, encrypted with a passphrase.
• Proton Mail stores private keys on Proton’s servers, encrypted with your account password.

Default Algorithms

KeychainPGP defaults to Ed25519 for signing and X25519 for encryption — the current best practice for new key generation. GnuPG 2.4+ also defaults to Ed25519/Cv25519, but many users still carry legacy RSA-2048 keys. Proton Mail has migrated most accounts to X25519. Mailvelope and OpenKeychain support ECC but often default to RSA-2048 or RSA-4096 in their key generation wizards.

Ease of Use Comparison

A PGP tool’s security means nothing if its complexity drives users to skip encryption altogether. Here is how each tool handles the first-time experience.

Setup Time

• KeychainPGP: Try the web app with no installation, or download the native desktop/Android app from GitHub. Generate a key and start encrypting. Total time: under two minutes.
• GnuPG: Requires installation via package manager or binary download. Key generation uses gpg --full-generate-key. Total time: five to fifteen minutes depending on familiarity.
• Gpg4win: Download and install a 30+ MB package. Launch Kleopatra, walk through the key creation wizard. Total time: five to ten minutes.
• GPG Suite: Download from gpgtools.org, install the package. Open GPG Keychain to generate keys. Total time: five to ten minutes.
• Mailvelope: Install the browser extension, configure it for your webmail provider. Generate or import keys. Total time: three to five minutes.
• OpenKeychain: Install from F-Droid or Google Play. Create key through the guided wizard. Total time: three to five minutes.
• Proton Mail: Create a Proton account. Keys are generated automatically. Total time: two to three minutes, but you are locked into the Proton ecosystem.

Learning Curve

GnuPG has the steepest learning curve by far. Its command-line interface offers hundreds of options, and even experienced users regularly consult documentation for less common operations. Gpg4win’s Kleopatra GUI helps, but it exposes much of GnuPG’s underlying complexity.

KeychainPGP and Proton Mail sit at the opposite end of the spectrum. KeychainPGP’s interface is intentionally minimal: paste text, click encrypt, copy the result. Proton Mail abstracts PGP away entirely — users may not even realize they are using PGP.

Mailvelope and OpenKeychain fall in the middle. Both offer guided workflows but require the user to understand concepts like public and private keys, key IDs, and trust models.

First Encryption Experience

The path to a successful first encryption is perhaps the most revealing test of usability. With KeychainPGP, you paste a recipient’s public key and your plaintext, then click a button. With GnuPG, you must first import the recipient’s key (gpg --import), verify the fingerprint, set trust, and then run gpg --encrypt --recipient. The number of steps and decisions involved is a real barrier for non-technical users.

Platform Support Comparison

Platform availability can be a deciding factor, especially for users who work across multiple devices.

KeychainPGP runs natively on Windows, macOS, Linux, and Android, with a web app for browsers and a CLI for headless use. This makes it the most broadly available option in this PGP tools comparison. The web app compiles Sequoia-PGP to WebAssembly, so it also works on Chromebooks, tablets, and any device with a browser.

GnuPG is available on Linux, macOS, and Windows, but mobile support is absent. You can install it via apt, brew, or the Gpg4win installer, respectively.

Gpg4win is Windows-only. GPG Suite is macOS-only. Each fills a platform gap for GnuPG’s GUI, but neither crosses over to other operating systems.

Mailvelope works wherever Chrome, Firefox, or Edge runs, but it is limited to webmail contexts — you cannot use it to encrypt arbitrary files or clipboard text.

OpenKeychain is Android-only. There is no official iOS equivalent with comparable functionality, which leaves iPhone users underserved in the open-source PGP mobile space.

Proton Mail covers web, iOS, and Android with dedicated native apps, making it the strongest option for mobile email encryption specifically — though it is not a general-purpose PGP tool.

Detailed Analysis

KeychainPGP

KeychainPGP is a modern, cross-platform PGP tool built on Rust and Sequoia-PGP. The desktop and Android apps use Tauri v2, the web app compiles the same Rust engine to WebAssembly, and the CLI provides a headless interface for scripting. It represents a new approach to PGP software that prioritizes accessibility without sacrificing security.

Strengths:

• Clipboard-first workflow. Copy text, press a global hotkey, paste the encrypted result. Works from any application on your system — email, chat, notes, web forms.
• Full platform coverage. Native apps for Windows, macOS, Linux, and Android. A zero-install web app for browsers. A CLI (keychainpgp) for scripting and automation.
• Modern cryptographic defaults. Ed25519 for signing and X25519 for encryption out of the box. Users do not need to understand algorithm selection to get strong security.
• OPSEC mode. An optional operational security mode with RAM-only keys, window title disguise, panic wipe, and Tor/SOCKS5 proxy support for key-server lookups.
• Memory-safe foundation. Sequoia-PGP is written in Rust, eliminating entire classes of memory-corruption vulnerabilities.
• QR code key sync. Transfer keys between desktop and mobile devices via QR codes — no cloud, no key servers required.

Limitations:

• No native email integration (though clipboard-based workflows are compatible with any email client).
• Newer project with a smaller community than GnuPG.

For a full list of PGP tools and their ecosystems, see our PGP Tools documentation.

GnuPG (GPG)

GnuPG is the oldest and most widely deployed OpenPGP implementation. It is the reference standard against which all other tools are measured.

Strengths:

• Widest algorithm support. RSA, DSA, ElGamal, Ed25519, Cv25519, Brainpool, and NIST curves. If an OpenPGP algorithm exists, GnuPG almost certainly supports it.
• Mature key management. The GPG agent handles passphrase caching, SSH key integration, and smartcard support (YubiKey, Nitrokey).
• Extensive ecosystem. Hundreds of tools and scripts integrate with GnuPG. It is the backbone of Linux package signing, Git commit signing, and pass (the standard Unix password manager).
• Battle-tested. Over 25 years of real-world use, security audits, and continuous development.

Limitations:

• Steep learning curve. The CLI is powerful but opaque.
• Written in C, which means ongoing risk of memory-safety vulnerabilities.
• Configuration is complex. The gpg.conf and gpg-agent.conf files contain dozens of options that can interact in surprising ways.
• No built-in GUI.

To understand the relationship between PGP the standard and GPG the software, read our PGP vs. GPG explainer.

Gpg4win

Gpg4win packages GnuPG with the Kleopatra certificate manager and an Outlook plugin (GpgOL) into a single Windows installer.

Strengths:

• Provides a graphical interface for key management, encryption, and signing on Windows.
• Outlook integration allows one-click email encryption for business users.
• Maintained by the German Federal Office for Information Security (BSI), which adds institutional credibility.
• Includes a file encryption component (GpgEX) that adds right-click encrypt/sign options in Windows Explorer.

Limitations:

• Windows-only.
• Kleopatra’s interface, while functional, exposes much of GnuPG’s complexity and can overwhelm new users.
• Inherits all of GnuPG’s C-based security profile.
• The Outlook plugin can be unreliable across different Outlook versions and update cycles.

GPG Suite

GPG Suite is the macOS counterpart to Gpg4win, offering GPG Keychain for key management and GPGMail for Apple Mail integration.

Strengths:

• Native macOS look and feel. GPG Keychain integrates well with the macOS experience.
• Apple Mail plugin allows transparent encryption and signing for macOS users who prefer the built-in email client.
• Simple key generation wizard for new users.

Limitations:

• macOS-only.
• The GPGMail plugin requires a paid license (currently a one-time purchase). This makes GPG Suite the only tool in this comparison with a mandatory cost for full functionality.
• Apple Mail integration can break with major macOS updates, as Apple does not officially support mail plugins.
• Partially open source — the GPGMail component is proprietary.

Mailvelope

Mailvelope is a browser extension that adds PGP encryption to webmail providers like Gmail, Outlook.com, and Yahoo Mail.

Strengths:

• Integrates directly into webmail interfaces. Users can compose encrypted emails without leaving their browser or switching tools.
• Supports key server lookups for discovering recipients’ public keys.
• Open-source under AGPLv3.
• Low barrier to entry for webmail users.

Limitations:

• Limited to webmail. Cannot encrypt files, clipboard text, or anything outside the email context.
• Browser extensions have an inherently larger attack surface than native applications. A compromised browser can expose private keys.
• Key storage in browser local storage is less secure than OS-level key stores.
• Performance can lag with large messages or attachments because OpenPGP.js runs in JavaScript.

OpenKeychain

OpenKeychain is the leading open-source PGP app for Android, with deep integration into the K-9 Mail email client (now Thunderbird for Android).

Strengths:

• Best-in-class Android PGP experience. Integrates with K-9 Mail / Thunderbird for Android for transparent email encryption.
• NFC-based key transfer between devices.
• Hardware security key support via USB OTG.
• Clean, well-designed Material UI.

Limitations:

• Android-only. No iOS version.
• Development pace has slowed in recent years, with longer gaps between releases.
• Limited to the Android ecosystem means it cannot serve as a primary tool for desktop users.

Proton Mail

Proton Mail is an encrypted email service that uses PGP under the hood, abstracting away the complexity entirely.

Strengths:

• Zero-knowledge encryption. Proton cannot read your email content.
• PGP is completely invisible to the user. No key management, no configuration, no learning curve.
• Cross-platform with polished native apps for iOS and Android.
• Supports external PGP keys for communicating with non-Proton users.

Limitations:

• Centralized. Your private keys are stored on Proton’s servers (encrypted with your password). You must trust Proton’s infrastructure and jurisdiction (Switzerland).
• Not a general-purpose PGP tool. You cannot use Proton Mail to encrypt files, sign documents, or perform arbitrary PGP operations.
• Free tier is limited. Full functionality requires a paid subscription.
• Vendor lock-in. Moving away from Proton means exporting keys and migrating your email address.

Which PGP Tool Should You Choose?

After this detailed comparison of PGP encryption software, the right choice depends on your specific needs. Here is a summary:

• For most users, KeychainPGP offers the best balance of security, usability, and accessibility. Its modern Rust/Sequoia foundation, zero-install browser deployment, and sensible cryptographic defaults make it the easiest way to use strong PGP encryption today. If you have ever been intimidated by GnuPG or frustrated by platform-specific tools, KeychainPGP is worth trying first.
• For power users and developers who need scripting, automation, Git signing, or smartcard support, GnuPG remains indispensable. Pair it with Gpg4win on Windows or GPG Suite on macOS for a GUI.
• For mobile-first Android users, OpenKeychain combined with K-9 Mail provides a solid encrypted email workflow.
• For non-technical users who only need encrypted email, Proton Mail hides all complexity at the cost of centralization and vendor lock-in.
• For webmail users who want to add PGP to Gmail or Outlook.com without switching providers, Mailvelope fills a unique niche.

No single tool is perfect for every scenario. Many security-conscious users maintain two or more PGP tools — for example, KeychainPGP for quick encryption tasks and GnuPG for Git commit signing. The important thing is to actually use encryption, and the tool that makes that easiest for your workflow is the right one.

For more recommendations, see our roundup of the best PGP tools in 2026 or explore the full PGP tools ecosystem.