OpenPGP Message Encryptor
Last Updated: June 28, 2026
OpenPGP Message Encryptor
Encrypt, decrypt, sign, and verify messages using OpenPGP.js. 100% browser-side processing.
OpenPGP Message Encryptor
Encrypt, decrypt, sign, and verify messages using OpenPGP.js. All cryptographic operations happen in your browser. Compatible with GnuPG, Proton Mail, Mailvelope, and Thunderbird.
Public Key(s)
Paste armored public keys or drag & drop .asc / .pgp / .gpg / .txt files
Sign Message (Optional)
Processing
Initializing...Security Dashboard
Key Fingerprint
Verify this fingerprint with the sender through a separate channel.
Signature Verification
Downloads
Privacy & Security
All cryptographic operations execute locally via OpenPGP.js in a Web Worker.
Recipients
Encrypt, decrypt, sign, and verify messages using OpenPGP in your browser. Supports multi-recipient encryption, digital signatures, and GnuPG-compatible keys — all processed locally.
How To Use
Follow these simple steps to get started with openpgp message encryptor.
Choose your mode
Select Encrypt, Decrypt, Sign, Verify, Sign+Encrypt, or Decrypt+Verify from the segmented control.
Enter your message
Type or paste your plaintext message or PGP armored message into the message input area.
Add your keys
Paste recipient public keys, your private key, or signer's public key — drag & drop .asc/.pgp/.gpg/.txt files supported.
Configure options
Enable signing, detached signatures, or add a passphrase for private key decryption as needed.
Process and share
Click the action button, review the output, download .asc files, copy results, or share the encrypted/signed message.
Real-World Examples
Practical situations where openpgp message encryptor helps solve real problems.
Secure Email Communication
Encrypt email messages before sending through unencrypted channels. Recipients with PGP-configured email clients can decrypt using their private key.
Message Integrity Verification
Sign important messages and documents with your private key. Recipients verify your signature using your public key, confirming the message hasn't been tampered with.
Team Collaboration Encryption
Encrypt sensitive team communications for multiple recipients. Each team member with a private key can decrypt the shared message independently.
Secure File Descriptions & Metadata
Encrypt file descriptions, metadata, and instructions before sharing alongside encrypted files for comprehensive secure communication.
Why Use This Tool
Discover how this tool can improve your workflow and productivity.
Six Powerful Modes
Encrypt, decrypt, sign, verify, sign+encrypt, and decrypt+verify — all six OpenPGP operations in a single tool with smooth mode switching and persistent preferences.
Multi-Recipient Encryption
Encrypt messages for one or more recipients by adding multiple public keys. Each recipient can decrypt the message with their own private key.
Digital Signatures & Verification
Sign messages with your private key and let recipients verify authenticity with your public key. Supports both inline and detached signatures.
GnuPG & ProtonMail Compatible
ASCII-armored output that works with GnuPG, Proton Mail, Mailvelope, Thunderbird, OpenKeychain, Kleopatra, and any OpenPGP-compatible software.
Enterprise-Grade Cryptography
AES-256 encryption, SHA-256 hashing, RSA/ECC key support, and RFC 4880 compliant operations via OpenPGP.js 5.x — the same library trusted by Proton Mail.
Zero-Knowledge Architecture
Messages, keys, passphrases, and signatures never leave your browser. All cryptographic operations execute in a Web Worker. No uploads, no servers, no logs.
Common Use Cases
Practical scenarios where this tool can help you get things done.
Secure Email Communication
Encrypt email messages before sending through unencrypted channels. Recipients with PGP-configured email clients can decrypt using their private key.
Message Integrity Verification
Sign important messages and documents with your private key. Recipients verify your signature using your public key, confirming the message hasn't been tampered with.
Team Collaboration Encryption
Encrypt sensitive team communications for multiple recipients. Each team member with a private key can decrypt the shared message independently.
Secure File Descriptions & Metadata
Encrypt file descriptions, metadata, and instructions before sharing alongside encrypted files for comprehensive secure communication.
Tool Summary
Quick facts about this tool at a glance.
What Is OpenPGP Message Encryptor?
An OpenPGP Message Encryptor is a browser-based tool that encrypts, decrypts, signs, and verifies messages using the OpenPGP standard (RFC 4880) via OpenPGP.js. It supports six operating modes — Encrypt, Decrypt, Sign, Verify, Sign+Encrypt, and Decrypt+Verify — with multi-recipient encryption, detached signatures, and full compatibility with GnuPG, Proton Mail, Mailvelope, Thunderbird, and other OpenPGP software. All cryptographic operations execute in a Web Worker, ensuring messages, keys, and passphrases never leave the browser.
About This Tool
What Is OpenPGP?
OpenPGP (Open Pretty Good Privacy) is the open-standard encryption protocol defined in RFC 4880. It lets you encrypt messages, digitally sign content, and verify the identity of the people you're communicating with. Think of it as a tamper-proof digital envelope: only the intended recipient has the key to open it, and everyone can check that it hasn't been opened or altered in transit.
Unlike messaging apps that lock you into their ecosystem, OpenPGP works across any platform. You can encrypt an email on your phone, send it to someone using completely different software on a Windows PC, and it just works. That's the power of an open standard.
Why Use a Browser-Based OpenPGP Encryptor?
You might be wondering: why encrypt a message in a browser instead of using a desktop app like GnuPG or Kleopatra? Good question. The answer comes down to convenience, speed, and zero setup.
Most encryption tools require you to install software, generate keys through a command line, and fumble with file formats. This tool skips all of that. Open your browser, paste your message, select your operation, and you're done. No installation. No configuration. No waiting.
But here's the best part: everything runs locally. OpenPGP.js (the same library Proton Mail uses) executes entirely in your browser inside a Web Worker. Your message, your private key, your passphrase - none of it ever touches a server. You get the full power of PGP encryption without the setup headache and without sacrificing privacy.
How Does OpenPGP Encryption Work?
OpenPGP combines two cryptographic techniques: asymmetric encryption (public-key crypto) and symmetric encryption (shared-secret crypto). It works in layers, and understanding those layers helps you use the tool like a pro.
When you encrypt a message for someone, OpenPGP.js generates a unique session key: a one-time random password just for that message. It encrypts your actual message with that session key using AES-256, one of the strongest symmetric ciphers available. Then it encrypts the session key itself with each recipient's public key using RSA or ECC. The result is an ASCII-armored block of text that starts with -----BEGIN PGP MESSAGE----- and ends with -----END PGP MESSAGE-----.
Why the two-step approach? Asymmetric encryption is slow and limited in how much data it can handle directly. By using it only to protect the session key, OpenPGP gets the security of public-key crypto with the speed of symmetric encryption. Smart, right?
For signing, the process is different. OpenPGP.js creates a hash (a cryptographic fingerprint) of your message using SHA-256, then encrypts that hash with your private key. Anyone with your public key can decrypt the hash, recompute it from the message, and confirm the two match. If the message is altered even slightly, the hash changes and the signature breaks. That's how you know the message is authentic and wasn't tampered with.
Who Should Use This Tool?
This tool is for anyone who needs to send or verify encrypted communications but doesn't want to deal with complex desktop software.
Journalists and whistleblowers use OpenPGP to protect sensitive sources and communicate securely when their lives depend on it. They need tools that work without a trace and don't leave digital footprints on their devices.
Security professionals encrypt sensitive client communications, verify software authenticity through signed releases, and audit PGP configurations - all from a browser when they're on the go.
Enterprise teams use PGP encryption for regulatory compliance. GDPR, HIPAA, and PCI-DSS all require data protection measures, and OpenPGP is a proven, auditable way to meet those requirements.
Developers sign Git commits and software packages with PGP keys. They verify upstream signatures before integrating third-party code into their projects. Having a browser-based verifier means they can check signatures without installing GPG on every machine.
Privacy-conscious individuals encrypt personal emails, share confidential documents, and protect their digital communications from surveillance, data breaches, and unauthorized access.
Students and researchers exploring cryptography use this tool to understand how PGP operations work in practice without needing to install command-line tools.
Why Trust This OpenPGP Message Encryptor?
Trust is everything when it comes to encryption. Here's why you can rely on this tool:
Zero data leaves your browser. OpenPGP.js runs in a Web Worker - a background thread that keeps the UI responsive while the cryptographic operations execute. The worker fetches the OpenPGP.js library from a CDN once when the page loads, then all operations happen in memory. No data is stored, logged, transmitted, or cached anywhere.
OpenPGP.js 5.x is the battle-tested library used by Proton Mail, one of the world's most popular encrypted email services. It's open source, actively maintained, and audited by security researchers.
GnuPG-compatible output means you can encrypt with this tool and decrypt with gpg --decrypt on any system. There's no vendor lock-in, no proprietary format, no surprises.
Getting Started
Open the tool in your browser. You'll see six operation buttons at the top: Encrypt, Decrypt, Sign, Verify, Sign+Encrypt, and Decrypt+Verify. Select the one you need, and the interface adjusts to show the relevant controls.
For encryption, paste the recipient's public key (or upload a .asc or .gpg key file), type or paste your message, and click the Encrypt button. The encrypted output appears instantly. Copy it or download it as an .asc file.
For decryption, paste your own private key, enter your passphrase, paste the PGP message, and click Decrypt. The decrypted message appears in the output panel.
For signing, paste your private key and passphrase, type your message, and click Sign. The signed output includes both the message and the signature in one block, or you can generate a detached signature file (a separate .sig file) that can be shared alongside the original message.
For verification, paste the sender's public key, paste the signed message (or the message plus detached signature), and click Verify. The tool tells you whether the signature is valid and who signed it.
That's it. No complex menus, no confusing options. Six operations, each with a clear purpose and a simple interface.
Understanding the Six OpenPGP Operations
Encrypt: Scramble a message so only the intended recipients can read it. You need each recipient's public key. The output is ASCII-armored text safe for email, chat, or any text channel. You can encrypt for one recipient or ten - the tool handles any number of public keys.
Decrypt: Reverse the encryption using your private key and passphrase. If your private key is encrypted (and it should be), the tool asks for your passphrase to unlock it before decrypting.
Sign: Prove you wrote a message. Signing attaches your cryptographic signature to a message, allowing anyone with your public key to confirm the message came from you and hasn't been altered. Signing does not encrypt the message - it remains readable.
Verify: Confirm a signature is valid using the sender's public key. Verification tells you three things: who signed it (based on the key's identity), that it's authentic (the signature matches the message), and that it hasn't been modified (the hash matches).
Sign+Encrypt: Sign first, then encrypt. This gives you authenticated encryption: the recipient can decrypt the message and verify it came from you in one step. This is the recommended approach for most secure communications.
Decrypt+Verify: Decrypt the message, then verify the embedded signature. If both succeed, you have the plaintext and cryptographic proof of the sender's identity.
Key Management Guide
Your keys are the foundation of everything OpenPGP does. Here's what you need to know:
Public keys are meant to be shared. Distribute them via email signatures, key servers (like keys.openpgp.org), your website, or social media profiles. The more places your public key is available, the easier it is for people to encrypt messages to you.
Private keys must stay secret. Never share your private key with anyone. Store it in a secure location: an encrypted file on your computer, a hardware security key, or a password manager that supports file attachments. Your private key should always be protected by a strong passphrase.
Key fingerprints are short identifiers (like 4A3C 5E6F 7B8C 9D0E 1F2A 3B4C 5D6E 7F8A 9B0C 1D2E) that uniquely identify a public key. When you paste a key into the tool, it extracts and displays the fingerprint. Verify fingerprints through a separate communication channel (a phone call, a different messaging app) to confirm you have the right key.
Key types: RSA 2048-bit and 4096-bit keys are the most common and broadly compatible. ECC (Elliptic Curve Cryptography) keys using Curve25519 are newer, faster, and provide equivalent security with smaller keys. This tool supports both.
Real-World Use Cases
Protect sensitive email attachments by encrypting them as armored text that can be pasted directly into an email body or attached as an .asc file.
Verify downloaded software by checking the PGP signature on the release against the developer's public key. Most open-source projects publish signed checksums for their releases.
Authenticate identity during business transactions by signing a contract document or a verification message that proves you control your private key.
Secure DevOps workflows by having team members encrypt secrets and configuration files using a shared team public key, ensuring only authorized members can decrypt them.
Comply with data protection regulations by encrypting personal data before transmission. OpenPGP encryption is recognized as an appropriate technical measure under GDPR Article 32.
Comparison with Alternatives
How does this tool stack up against other PGP solutions?
GnuPG is the gold standard for desktop PGP operations. It's powerful, scriptable, and battle-tested. But it requires installation, command-line familiarity, and manual key management. This tool is complementary: use GnuPG for your daily workflow, and use this browser tool when you're on a machine without GPG installed.
Proton Mail provides integrated PGP encryption in a webmail interface. It's excellent for email, but it can't encrypt arbitrary messages or files for non-Proton users. This tool handles any message, any key, any recipient.
Mailvelope is a browser extension that integrates PGP into webmail. It's convenient for email, but you need to install the extension in each browser. This tool requires no installation and works on any device with a modern browser.
Desktop GUI tools like Kleopatra and OpenKeychain are great for users who prefer graphical interfaces. But they tie you to specific operating systems. This tool works on Windows, macOS, Linux, ChromeOS, Android, and iOS - anywhere there's a browser.
Security Best Practices
Always use strong passphrases for your private keys. A passphrase like correct-horse-battery-staple is far more secure than P@ssw0rd! and easier to remember. Aim for at least 12 characters with a mix of words, numbers, and symbols.
Verify fingerprints through a separate channel. If someone sends you their public key via email, don't trust that it's really theirs. Call them, message them on a different platform, or check their website. Compare the fingerprint the tool displays against what they say their fingerprint is.
Use Sign+Encrypt instead of just Encrypt. Encryption alone keeps the message secret, but it doesn't prove who sent it. Sign+Encrypt gives you both confidentiality and authentication, which is what most secure communication scenarios need.
Keep your OpenPGP.js version current. Browser-based tools pick up updates when the page loads, so you always get the latest version of the library with the newest security patches.
Be careful with detached signatures. A detached signature is a separate .sig file that must be kept alongside the original message. If you lose the signature, you lose the ability to verify. Attached signatures (where the signature is bundled with the message) are simpler to manage.
Troubleshooting Common Issues
Key parsing fails: Make sure your key is in ASCII-armor format (starts with -----BEGIN PGP PUBLIC KEY BLOCK----- or -----BEGIN PGP PRIVATE KEY BLOCK-----). Binary key files (.gpg) must be converted to ASCII-armor first.
Decryption fails with wrong passphrase: Check that the passphrase matches the passphrase used when the key was created. Passphrases are case-sensitive. If you've forgotten your passphrase, the key is unrecoverable - there's no way to reset it.
Signature verification fails: Confirm you have the correct public key for the sender. The signature might be valid but from a different key than you expect. Check the key ID in the verification result against the sender's key fingerprint.
Empty output after decryption: The message might be encrypted with a key that doesn't match any of your private keys. Check that you're using the correct private key and that the message was encrypted with the matching public key.
Advanced Tips
For batch operations, you can prepare plaintext messages in advance and encrypt them one at a time. The tool processes each operation independently, so you can work through a queue of messages efficiently.
To encrypt the same message for multiple teams, create separate group public keys. Encrypt the message once for each group key, producing different ciphertext blocks for each audience.
Use the download feature to save encrypted messages as .asc files or signatures as .sig files. These files can be attached to emails or uploaded to servers just like any other file.
Combine this tool with a password manager that stores your private keys as file attachments. Copy the key from your password manager, paste it into the tool, perform your operation, and never store the key on your device's filesystem.
Compatibility
The tool produces OpenPGP-compliant output that works with GnuPG (gpg --decrypt, gpg --verify), Proton Mail, Mailvelope, Thunderbird with built-in OpenPGP, OpenKeychain for Android, Kleopatra for Windows, and any software implementing RFC 4880. Messages encrypted in this tool can be decrypted on any system that supports OpenPGP.
Ready to get started? Pick an operation above, paste your key, and send your first encrypted message. It takes about thirty seconds, and after that, you'll wonder why you didn't start using PGP sooner.
Quick Summary
This free OpenPGP Message Encryptor performs six PGP operations entirely in your browser via OpenPGP.js 5.x in a Web Worker. Encrypt messages for one or more recipients using their public keys (AES-256 / RSA-2048/4096 or ECC). Decrypt messages with your private key and passphrase. Sign messages to prove authorship and integrity. Verify signatures using the sender's public key. Combine sign+encrypt for authenticated encryption. Combine decrypt+verify to decrypt and authenticate in one step. Features include multi-recipient support (any number of public keys), GnuPG-compatible ASCII-armored output, detached signature generation, drag-and-drop key file upload (.asc/.pgp/.gpg/.txt), code-style text editors with char/word counting and fullscreen mode, a security dashboard showing algorithm, cipher (AES-256), hash (SHA-256), recipients count, and processing duration, key validation and fingerprint display, and downloadable output as .asc or .sig files. All data stays local — zero uploads, zero server requests, complete privacy.
Related Concepts
Explore related terms and topics associated with openpgp message encryptor.
Frequently Asked Questions
Common questions about openpgp message encryptor.
How do I encrypt a message using OpenPGP online?
Select 'Encrypt' mode, paste your message in the input area, add one or more recipient PGP public keys in the Public Key(s) field, and click 'Encrypt Message'. The tool uses OpenPGP.js to encrypt the message with AES-256 and returns an ASCII-armored PGP message starting with '-----BEGIN PGP MESSAGE-----'. Copy or download the encrypted output to share with your recipients.
How do I decrypt a PGP message in my browser?
Switch to 'Decrypt' mode, paste the PGP encrypted message (the ASCII-armored block starting with '-----BEGIN PGP MESSAGE-----') into the message input, add your private key, enter your passphrase, and click 'Decrypt Message'. The tool decrypts the message locally using OpenPGP.js and displays the plaintext. Your private key and passphrase never leave your browser.
Can I encrypt a message for multiple recipients?
Yes. Paste multiple PGP public keys into the Public Key(s) field — one after another or separated by blank lines. The tool encrypts the message so that each recipient can decrypt it with their own private key. The security dashboard shows the number of recipients the message was encrypted for.
How do I sign a message with PGP?
Select 'Sign' mode, type your message, add your private key, enter your passphrase, and click 'Sign Message'. The tool returns an ASCII-armored signed message. Enable 'Detached Signature' to generate a separate .sig file instead of an inline signature. Recipients can verify your signature using your public key.
How do I verify a PGP signature?
Select 'Verify' mode, paste the signed message or the original message (for detached signatures), add the signer's public key, and click 'Verify Signature'. The tool verifies the cryptographic signature and displays whether it's valid or invalid. For detached signatures, enable the Detached Signature toggle and paste the .sig content.
Is this tool compatible with GnuPG and GPG?
Yes. This tool uses OpenPGP.js, which implements the OpenPGP standard (RFC 4880). The ASCII-armored output is fully compatible with GnuPG, GPG, Proton Mail, Mailvelope, Thunderbird Enigmail, OpenKeychain (Android), Kleopatra (Windows), and any OpenPGP-compatible software. You can encrypt with this tool and decrypt with GnuPG, and vice versa.
What encryption algorithm does this tool use?
By default, OpenPGP.js uses AES-256 for symmetric encryption (the actual message encryption), SHA-256 for hashing, and the recipient's public key algorithm (RSA or ECC) for key encryption. This provides strong security: AES-256 is the current standard for government and enterprise encryption, and SHA-256 ensures message integrity.
Are my messages and keys uploaded to a server?
No. All cryptographic operations — encryption, decryption, signing, verification, and key processing — execute entirely in your browser using OpenPGP.js running in a Web Worker. Your messages, keys, passphrases, and signatures never leave your device. There are no uploads, no server requests, no logging, and no telemetry. This is a zero-knowledge tool.
Can I use my existing GPG keys from GnuPG?
Yes. Export your existing keys from GnuPG (gpg --export --armor for public keys, gpg --export-secret-keys --armor for private keys), copy the ASCII-armored blocks, and paste them into the tool. The keys are parsed and validated by OpenPGP.js locally in your browser. The tool supports both RSA and ECC (Ed25519, Curve25519, NIST P-256/P-384) key types.
What is the difference between Sign and Sign+Encrypt?
'Sign' generates a signed message that anyone with your public key can read and verify. 'Sign+Encrypt' first signs the message with your private key, then encrypts it with the recipient's public keys — so only the intended recipients can decrypt and read it (and they can verify it came from you). Use Sign+Encrypt when you need both confidentiality and authentication.
Can I verify a signature without decrypting?
Yes. Use 'Decrypt+Verify' mode to decrypt the message and verify the signature simultaneously. The tool checks if the message was signed by the expected sender by verifying the signature against the provided public key(s). The verification results panel shows whether each signature is valid or invalid.
What key formats are supported?
The tool supports ASCII-armored OpenPGP keys: '-----BEGIN PGP PUBLIC KEY BLOCK-----' for public keys and '-----BEGIN PGP PRIVATE KEY BLOCK-----' for private keys. Keys exported from GnuPG, Proton Mail, Mailvelope, and OpenKeychain work directly. Both RSA (2048, 3072, 4096-bit) and ECC (Ed25519, Curve25519, NIST P-256, P-384, P-521) keys are supported.
What is the output format?
Encryption and signing produce ASCII-armored output: '-----BEGIN PGP MESSAGE-----' for encrypted messages, '-----BEGIN PGP SIGNED MESSAGE-----' for signed messages, and '-----BEGIN PGP SIGNATURE-----' for detached signatures. The output is plain text that can be copied, saved as .asc files, or pasted into any OpenPGP-compatible application.
Is my data safe when using this tool?
Yes. This tool uses a zero-knowledge architecture: all crypto operations happen in a Web Worker running OpenPGP.js 5.x, the same library used by Proton Mail. Messages, keys, passphrases, and signatures never leave your browser. No data is stored, logged, cached, or transmitted. The only data persisted locally is your preferred mode (via localStorage).
Can I use this tool from my mobile phone?
Yes. The tool uses a responsive mobile-first layout that adapts from a 3-column desktop layout to a stacked mobile layout. The segmented control for 6 modes wraps on small screens. The editor supports touch input, and drag-and-drop works on mobile browsers. All processing is local, so no internet connection is needed after the initial page load.
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Reviewed by FreeDeskTools Editorial Team
OpenPGP Message Encryptor has been reviewed for accuracy, usability, privacy, and browser-side performance. FreeDeskTools tools are designed to run locally whenever possible, helping users complete tasks quickly without unnecessary data collection.
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