🧅
Truly peer-to-peer
Each copy of Seal Chat has its own Tor .onion address. Messages travel directly to your contact's computer — no relay, no cloud, nothing in the middle.
No servers · No accounts · Your own key
Private chat that goes straight from your PC to theirs.
Seal Chat sends messages, photos, videos and files directly between computers over the Tor network. Every message is signed and encrypted with your own PGP key, and nothing is ever stored on anyone's server — because there isn't one.
Free for Windows 10/11, macOS 13+, 64-bit Linux and Android 7+.
🧅 Tor .onion addresses🔐 OpenPGP — bring your own key📎 Files up to 4 GB📱 QR codes to connect🪟 Windows · 🍎 macOS · 🐧 Linux · 🤖 Android🌐 On your phone, via your own site
Everything a private messenger should be
Seal Chat is built around one idea: your conversations belong to the two people having them.
🔑
Your own PGP key
Import the OpenPGP key you already use (RSA or modern ECC) or let Seal Chat create one. Every message is signed by you and encrypted to them.
📎
Photos, video, music, documents
Send any file up to 4 GB. Photos show in the chat, audio and video play right there, and broken transfers pick up where they stopped.
⏱
Works when they're offline
Messages wait in your outbox and go out by themselves the moment your contact's Seal Chat comes online — usually within seconds.
📷
Connect with a QR code
Show your QR code, send it as a picture, or scan theirs with your webcam. Your ID includes your key fingerprint, so nobody can pretend to be you.
✔
Verify who you're talking to
A 60-digit safety number, identical on both computers, lets you confirm by phone or in person that nobody is in the middle.
🖼
Pictures you control
Share your profile picture with contacts — or don't. And pick your own picture for anyone, whatever they share.
🔒
Locked on your computer
Chats, files and keys are encrypted on disk and tied to your Windows, Mac or Linux account. Add a PIN (or Windows Hello) for a second lock.
Up and running in three steps
- 1
Install and pick your key
Use your existing PGP private key or create a new one. Seal Chat starts its own built-in copy of Tor — nothing else to install, no router settings, no port forwarding.
- 2
Share your Seal Chat ID
In under a minute you get an ID like
sealchat:…onion:FINGERPRINTand a matching QR code. Send it to the people you want to talk to. - 3
Add each other and chat
They paste your ID or scan your QR code. Seal Chat checks the key at your address matches the fingerprint, sends a signed request, and once you accept — you're talking.
How your messages are protected
Layer on layer — and an honest list of what any serverless messenger can't do.
What Seal Chat does
- Signed and encrypted with OpenPGP: only your contact's key can open a message, and their copy proves it came from you.
- Inside Tor's own end-to-end encryption between the two .onion addresses — your contacts never learn your IP address or location.
- Files get their own random key; each 256 KB piece is sealed with AES-256-GCM and checked on arrival, so nothing can be altered, reordered or swapped.
- No server stores anything. There is no account to hack and no message archive to leak.
- Encrypted on disk, locked to your Windows account (DPAPI), your Mac's Keychain or your Linux keyring.
- Program files (.exe, .bat, .ps1 …) never download or open by themselves.
Good to know
- Both computers need to be on. With no server to hold messages, they travel when both copies of Seal Chat are running. Keep it in the tray — it sends and receives in the background.
- Tor is slower than normal internet — about 0.5–3 MB per second. Photos take seconds; a long video takes minutes, and resumes if interrupted.
- PGP has no "forward secrecy". If someone ever got your private key and its passphrase, they could read past messages they had recorded. Keep your key and backups safe.
- One computer per ID at a time. Use the encrypted backup to move to a new PC with the same ID.
Download Seal Chat
Version 1.9.5 · released October 21, 2026. Tor is built in — nothing else to install.
Windows
Windows 10 and 11, 64-bit
SHA-256 checksum
d08ef8b4ca842ae17b08c3093f2edb04b7062ee628fab1da0731599410ebff2fmacOS — Apple Silicon
Macs with M1, M2, M3, M4 … · macOS 13+
Which Mac do I have? · First start
SHA-256 checksum
4a19938ba95aafd1c8b99bc8a646b393395cdf959169960e36223f975374ad65Still on macOS 12 Monterey?
Only for Macs that can't upgrade to macOS 13 or newer. If yours can, use the download above.
- Built on an older engine (Electron 43). It gets security fixes only until that version is retired — after that, known security holes in it stay open.
- macOS 12 itself no longer gets security updates from Apple.
- It receives the same Seal Chat updates for now, but may stop getting new versions in the future.
Download the macOS 12 version (.dmg · 1.7.0, updates itself to 1.9.5 · 143 MB)
SHA-256 4c285c89120c1822c536d782f7e1cd348dc2039995b824b5b3cb9f28feae2e6f
macOS — Intel
Macs with an Intel processor · macOS 13+
Which Mac do I have? · First start
SHA-256 checksum
0ddfb5a7ba8b3d9b4ee32dc524dcf1e3e06ace06cf98133654bae34c3e65e165Still on macOS 12 Monterey?
Only for Macs that can't upgrade to macOS 13 or newer. If yours can, use the download above.
- Built on an older engine (Electron 43). It gets security fixes only until that version is retired — after that, known security holes in it stay open.
- macOS 12 itself no longer gets security updates from Apple.
- It receives the same Seal Chat updates for now, but may stop getting new versions in the future.
Download the macOS 12 version (.dmg · 1.7.0, updates itself to 1.9.5 · 150 MB)
SHA-256 fd7079f9cd8d95dab8567945d8fc9f22c42028cb40075c18ca1e98a66bb72b3a
Linux (.deb)
Ubuntu, Debian, Mint, Pop!_OS
SHA-256 checksum
7c60a6ff6a2cab26f4e7db4a9820f637348776dc7ce51b2b12b99df16061f0beLinux (AppImage)
Any 64-bit Linux
SHA-256 checksum
2ea02c24041859f1f79ad662801719be72995177bdff727a35b13a429ad2acbbUpdate file
Windows, macOS and Linux — already installed
SHA-256 checksum
53714540f19dc05d4ad8462c62beb091527b888a96f2a32c52cdb9e30aebf5a2Windows
Run the installer. If SmartScreen says "Windows protected your PC", click More info → Run anyway (the installer isn't code-signed).
macOS
Open the .dmg and drag Seal Chat onto Applications. The first time, macOS can't check the app — see first start on a Mac (one-time, about a minute).
Linux
sudo apt install ./SealChat-*.deb, or chmod +x the AppImage and run it. Have a desktop keyring (GNOME Keyring / KWallet) running.
Already installed?
Seal Chat 1.3 and newer tell you when an update is out and install it for you (signed and verified). Older versions: get the update file, then Settings → About & updates → Install update file… — one file works on Windows, macOS and Linux.
On an Android phone? Get the Android app. iPhone: Seal Chat Web adds a web interface on your own hosting. Need a hand? Read the help guide.
Seal Chat on a Mac
The same Seal Chat — same ID format, same encryption, built-in Tor — for macOS 13 Ventura and newer. It lives in the menu bar and works with your contacts on Windows and Linux.
1. Pick the right download
Click the Apple menu → About This Mac:
- "Chip: Apple M1, M2, M3, M4 …" → get macOS — Apple Silicon. Most Macs from late 2020 on.
- "Processor: … Intel …" → get macOS — Intel.
Picked the wrong one? The Intel version also runs on Apple Silicon (more slowly, through Rosetta) — the Apple Silicon version doesn't run on Intel Macs.
2. Install and open it the first time
- 1
Open the .dmg and drag Seal Chat onto Applications.
- 2
Open Seal Chat from Applications. macOS says it can't check the app ("Apple could not verify…") — click Done (or OK).
- 3
Open System Settings → Privacy & Security, scroll down and click Open Anyway next to Seal Chat, then confirm with your password.
- 4
That's it — from now on it opens normally, and updates install by themselves.
- Why the warning? Seal Chat isn't registered with Apple's paid developer program, so macOS can't vouch for it. It is the same app as on Windows and Linux; check the SHA-256 checksum under the download if you'd like to be sure the file is the one published here (
shasum -a 256 SealChat-*.dmgin Terminal). - Locked to your Mac account. Your key, chats and files are encrypted on disk with a key kept in your Mac's Keychain. To have Seal Chat start when you log in, tick Settings → App → Start Seal Chat when I log in to this Mac; it then waits in the menu bar.
Seal Chat on Android
The full Seal Chat — its own Tor .onion address, your own PGP key, the same encryption — running on your phone. It isn't in the Google Play Store, so you install it straight from this page. Android asks you to allow that once.
Install it
- 1
On your phone, open this page and tap Download on the Android app card. If Chrome warns that the file may be harmful, tap Download anyway.
- 2
Open the file: tap Open when the download finishes (or find SealChat-….apk in the Files app → Downloads).
- 3
Allow apps from this source. Android says it can't install apps from unknown sources: tap Settings, turn on Allow from this source, then go back. (It's for the app that opened the file — Chrome or Files. Android 7: Settings → Security → Unknown sources.)
- 4
Tap Install. If Google Play Protect asks to scan or says the app is unrecognised, tap More details → Install anyway — it only means the app isn't from the Play Store.
- 5
Open Seal Chat and tap Allow for notifications. When it asks to keep running in the background, allow it (battery: Unrestricted) — otherwise Android pauses it and messages arrive late.
- 6
New ID or your computer's? Create a new Seal Chat ID, or tap Link to my Seal Chat on another device: on your computer open Settings → Your devices → Link a new device… and type the code it shows into the phone. Your contacts and chats then appear on both.
- 7
Optional: turn Allow from this source back off (Settings → Apps → Chrome or Files → Install unknown apps). Seal Chat keeps working and updating.
Android app
Android 7.0 or newer · phones and tablets
SHA-256 checksum
9e394d1109994e8590d5f8dce990e200a1f26055771469b65d747c8db555276e- Updates itself — from the same signed update files as the desktop (Settings → About & updates), so you install the APK only once.
- Linking only works on a fresh install of the phone app — choose it on the first screen.
- Private storage. Your key and chats are encrypted with a key kept in the phone's Android Keystore.
- iPhone? There's no iPhone app — use Seal Chat Web.
Use Seal Chat in your phone's browser
Seal Chat Web is a small add-on you put on your own web hosting. Open it in your phone's browser and chat through the Seal Chat running on your computer — your key never leaves your computer.
📱
Your phone
The web interface in Safari or Chrome. Add it to your home screen and it opens like an app.
🌐
Your website
Seal Chat Web passes the sealed messages along. It can't read them and never has your key.
💻
Your computer
Seal Chat does the real work as always: your PGP key, Tor, your contacts and chats.
How it works
- A remote screen, not a copy. Your phone shows your contacts and chats and sends messages — Seal Chat on your computer actually signs, encrypts and delivers them over Tor.
- Paired with a QR code. Scan the code Seal Chat shows, choose a PIN, and check that the same 6-digit code appears on both screens before you approve.
- Sealed end to end between your phone and your computer (AES-256-GCM with a key made during pairing). Your website only ever stores sealed messages, and deletes them once picked up.
- Your PIN is checked by your computer. Ten wrong tries and that phone is removed. Remove any device in Seal Chat at any time.
- Contacts too. Add someone by scanning their QR code with your phone's camera, show your own QR code for them to scan, accept requests and check safety numbers — your computer does the checking, as always.
- Off until you turn it on — in Seal Chat (or from the tray icon), for good or for 1, 8 or 24 hours.
Good to know
- Your computer must be on, awake and running Seal Chat with web access turned on.
- Opening it takes a moment. While nobody uses the web interface, Seal Chat only checks for it every 30 seconds (you can choose 15 s – 5 min). Once connected, messages go both ways in a second or two.
- Almost no load on your website. Each idle check is one tiny request the web server answers by itself ("not modified") without running PHP — about 1–2 KB.
- Text, read ticks, pictures and files work on the phone: send photos, videos and files up to 100 MB, and open or save the ones in your chats (Seal Chat 1.7.0 + Seal Chat Web 1.2.0).
- Notifications (Seal Chat 1.6.0 + Seal Chat Web 1.1.0) say "New message" — or "New message from Alice" if you allow names — never the message itself. On iPhone they need the Home Screen version (iOS 16.4+).
- Keep your hosting account safe. Whoever controls your website's files controls the page your phone runs. They still couldn't get your key.
Install it on your hosting
- 1
Upload the Seal Chat Web folder to your hosting, e.g.
/public_html/chat/. Needs PHP 8 and https. - 2
Open
…/chat/admin.php. Enter the setup code (the page shows which file it is in — open it with your host's File Manager) and choose an admin password. - 3
Turn the web interface on and click Copy link.
- 4
In Seal Chat (1.4.0 or newer): Settings → Web access → paste the link → Connect → Turn on.
- 5
Pair your phone: click Pair a device…, scan the QR code with your phone's camera, choose a PIN, compare the code, and click Approve.
- 6
iPhone: open the page in Safari and tap Share → Add to Home Screen before pairing, then pair from the new icon — it opens like an app and stays paired.
Seal Chat Web
Web interface for your own web hosting
SHA-256 checksum
4d86359f11caef72977d852c720157dddc1e0d487fb1bd6f0ca22c5f990826deWorks with any shared hosting that runs PHP 8 over https (cPanel, LiteSpeed, Apache). No database. Settings are kept outside your public web folder.
Help & source code
A step-by-step guide with screenshots, and the complete source code for anyone who wants to check how Seal Chat works or build it themselves.
What's new in 1.9.5
- Android App side scrolling issue fixed
- Linked Devices (can only be linked when setting up a new account)
- Android App
- Mailbox support added through mutual contacts and optionally using a Cloudlfare worker.
- Emoji support added
- Phone notifications added for Seal Chat Web
- Add contacts from your phone: scan their QR code with your camera, or show your own QR code for them to scan
- Manage contacts on your phone: accept requests, rename, check safety numbers, mute, block or remove
- New installations update themselves to the latest version right away
- Bigger buttons and easier-to-read text in Seal Chat Web, sized for iPhone and Android
Questions
Is there really no server?
Right. Seal Chat uses Tor onion services: each copy publishes its own .onion address, and contacts connect to it directly. Your messages pass through Tor's volunteer relays in encrypted form, but no relay can read them or tell who is talking to whom — and nothing is stored anywhere except on the two computers.
Do I need to know PGP?
No. Seal Chat can create a key for you in one step. If you already have a PGP key (from GnuPG, Kleopatra, etc.), you can import it and keep using the same identity.
What if my contact is offline?
Your message waits in your outbox and is delivered the moment their Seal Chat starts or reaches you. Files work the same way, and large ones can arrive over several sessions.
Will it work on my network?
Most home networks work without any setup — no port forwarding needed. If a network blocks Tor (some workplaces, hotels or countries), add Tor bridges in Settings → Connection.
Does Seal Chat work on a Mac?
Yes — macOS 13 Ventura or newer, on both Apple Silicon (M1 and later) and Intel Macs (Macs that can't go past macOS 12 Monterey: see "Still on macOS 12?" in the macOS download card). Because it isn't registered with Apple, macOS asks you to allow it once in System Settings → Privacy & Security → Open Anyway. Step-by-step here.
Can Windows, Mac and Linux users talk to each other?
Yes. It's the same Seal Chat everywhere, so a contact on any of the three works exactly the same way.
Can I use it on two computers (or a computer and a phone)?
Yes (Seal Chat 1.9.0+): install Seal Chat on the new device, choose Link to my Seal Chat on another device on its first screen, and enter the code from Settings → Your devices → Link a new device… on the one you already use. Both then share your ID, contacts and chats. To move to a new computer instead, save an encrypted backup in Settings and restore it there.
Is there an Android app?
Yes — get it here (Android 7.0 or newer). It isn't in the Google Play Store, so Android asks you once to allow installing apps from your browser or Files app ("unknown sources"). It's the full Seal Chat with its own Tor address, and it updates itself from the same signed update files as the desktop. You can give it a new ID, or link it to the Seal Chat on your computer so both have your contacts and chats.
Is installing from "unknown sources" safe?
The setting only lets the one app you allow (e.g. Chrome) install apps; you can turn it off again right after installing. Get the APK only from this page, and if you'd like to be sure it's the published file, compare its SHA-256 checksum under the download. Updates after that are checked against Seal Chat's signing key before they're used.
Can I use Seal Chat in my phone's browser?
Yes, with Seal Chat Web on your own web hosting (Seal Chat 1.4.0 or newer; contacts and notifications on the phone need 1.6.0). Your phone becomes a remote screen for Seal Chat on your computer, so the computer has to be on and running Seal Chat. There's no app to install from an app store — it runs in Safari or Chrome, and you can add it to your home screen.
Can I send files from my phone?
Yes (Seal Chat 1.7.0 with Seal Chat Web 1.2.0): tap 📎 next to the message box to send photos, videos or files up to 100 MB. They go to Seal Chat on your computer in sealed pieces — your website can't read them — and your computer sends them to your contact over Tor. Files in your chats can be opened or saved on the phone too, also up to 100 MB; bigger ones open on your computer.
Can I get notifications on my phone?
Yes (Seal Chat 1.6.0 with Seal Chat Web 1.1.0): in Seal Chat Web open the menu ⋯ → Notifications. They say "New message" — or "New message from Alice" if you allow names — and never show the message itself. Seal Chat on your computer sends them, encrypted for that phone only, through your phone maker's push service; your website isn't involved. On iPhone and iPad they work in the Home Screen version (Safari → Share → Add to Home Screen, iOS 16.4 or newer).
Can the website read my messages?
No. Between your phone and your computer everything is sealed with a key made when you pair them, and the website only passes those sealed messages along. Your PGP key never leaves your computer. The one thing to protect is your hosting account itself: someone who could change the website's files could change the page your phone loads.
Do I need my own website for the phone version?
Yes — Seal Chat Web runs on web hosting you control (any host with PHP 8 and https, like a typical cPanel account). There's no central Seal Chat server, so your phone talks to your computer through your own site.
Can I see the source code?
Yes — download it here. It's the complete source of the app; the README inside explains how to build it.
How do I make sure I'm talking to the right person?
Open the contact's details (ⓘ) and compare the 60-digit safety number with them by phone or in person. If it matches on both computers, mark them as verified.