BLML
A private chat app for the people who actually matter to you — your family, your
close friends, your group.
No ads. No algorithms deciding what you see. No company reading your messages to
sell you things. BLML runs on a server you control, and your conversations,
photos and voice notes stay there.
Where it runs
iPhone and iPad, Android, and any web browser. All three talk to the
same server, so a conversation looks the same wherever you pick it up, and
history follows you between devices.
Every download is also gathered on blml.app, which reads
in Vietnamese or English.
Anyone can create an account on chat.blml.app: sign up with an email address,
then confirm it from the email you receive. If you run your own server you can
instead keep it invite-only with a registration code, so an address anyone can
reach need not be a room anyone can walk into.
On your phone
In your browser
What you can do with it
Talk to people
Message one person or a whole group. You get the things you expect from a modern
messenger: you can see when someone is typing, when your message was delivered,
and when it was read. Reply to a specific message to keep a busy group
conversation straight, edit a message you got wrong, or send a voice note when
typing is too slow.
Share photos, videos, documents and audio — up to 100 MB per file, which is
generous enough for a real video rather than a compressed smear of one.
There is a sticker and emoji panel next to the text box, opening on a page of
the ones people actually use: 👍 ❤️ 🎉 🎂 🙏 😂 and friends.
Call each other
Voice and video calls go directly between devices where the network allows it,
and fall back to relaying through your server when it doesn't — so calls
connect even when both people are on mobile data behind restrictive networks.
Keep a group organised
@mentions pull someone into a conversation they'd otherwise scroll past.
Pinned messages keep the address, the date, or the thing everyone keeps
asking about at the top where nobody has to search for it.
Polls let you settle "what are we eating" in one tap each, instead of
forty messages.
Broadcast channels are for announcements: admins post, everyone reads, and
nobody can derail it.
Link previews show you what a link actually is before you tap it — and the
title is fetched by your own server, so opening a chat doesn't quietly tell a
dozen websites that you're online.
Find each other
Every member has a personal QR code — scan one with the camera, or pick a
photo of one that was sent to you, and the chat opens. Add people by phone
number or email, search by username, or let the app match your phone's
contacts against members who've added their number. Nothing is uploaded
anywhere except your own server.
The app even suggests people you may know: members of your group chats
you haven't talked to one-on-one yet — the kind of suggestion that makes
sense in a family, computed on your phone rather than by an algorithm
watching you.
Make it yours
Light, dark, or follow-your-phone themes. A gallery of chat wallpapers served
from your own server, with matching light and dark versions so the app looks
right whichever theme you're in. Adjustable text size, because not everyone in a
family group has the same eyesight.
Saved messages
Every account gets a private space to send things to yourself — links, notes,
photos you want to find again later.
Why it works this way
Most chat apps are free because you are the product. BLML is the other trade:
someone runs a small server, and in return the group's messages belong to the
group.
That has real consequences worth being upfront about. There's no company
guaranteeing uptime — if the server goes down, chat stops until someone restarts
it. And whoever runs the server decides who gets in: open sign-up, or a code
you hand out yourself.
For a family spread across countries, or a group that just wants somewhere
quiet to talk, that's usually the right trade.
Running your own
The whole thing is open source and designed to run on one cheap server. A small
VPS is plenty — the software idles at around 110 MB of memory, so roughly
$10/month handles a hundred people comfortably.
Setting it up is three commands on a fresh Ubuntu machine, covered step by step
in deploy/DEPLOY.md. It brings up the server, gets an
HTTPS certificate automatically, sets up the call relay, and turns on nightly
backups.
Other documentation:
- SETUP.md — configuration, phone and email verification, push notifications
- BUILDING.md — building the iOS, Android and web clients yourself
License
BLML is open source. The server is licensed under the GNU GPL v3.0; the
iOS, Android and web clients under the Apache License 2.0. The license texts
are in server/LICENSE, ios/LICENSE, android/LICENSE and webapp/LICENSE,
and UPSTREAM.md records where the code comes from.
