Guide
How to deploy a Flask app cheaply
You built a Flask app and now it has to leave localhost and live somewhere with a real URL. Renting and configuring a server by hand is a lot of work for a small app, and a managed platform adds monthly minimums. Here's a cheaper, lower-effort way to put a Flask app online and keep it there.
The hard part isn't Flask — it's everything around it
Running flask run on your laptop is easy. Production is where it gets fiddly: a real WSGI server like gunicorn, a reverse proxy, TLS certificates, a process manager to restart it when it falls over, and a box to secure and patch. None of that is your app — it's plumbing. Sinkron handles the plumbing: you give it your app as a container, it runs across several machines behind one HTTPS URL with health checks and restarts, and there's no server for you to manage.
Deploy it in four steps
1. Add a Dockerfile (a few lines)
A minimal image starts from a Python base, installs your requirements, and runs a production server — for example pip install -r requirements.txt and a start command like gunicorn -b 0.0.0.0:8000 app:app. Bind to 0.0.0.0 and the port your session exposes. If you already build an image, use it as-is; the quickstart walks through it.
2. Add a little funding
Top up by card or USDC — no subscription, no minimum. You spend it down as the app runs, and whatever you don't use stays yours.
3. Deploy across the network
Point Sinkron at the image, choose a small CPU/RAM footprint, and pick how many runners. Your app comes up behind a single load-balanced HTTPS URL — no nginx, no certificates, no server to provision.
4. Pay only while it runs
Billing is per second of runtime. If your balance runs low we email you first, and if it hits zero your app stops so you're never billed past your deposit. Stop it yourself any time and the cost drops to zero.
Handling state: databases, files, sessions
Flask apps usually need a database or file storage, and your app runs across several interchangeable machines — so keep persistent data outside the container. Use a hosted database for your data and object storage (with your own S3 keys) for uploads. Keep server-side sessions in your database or a shared store rather than on local disk, since a user's next request may land on a different machine. Treat each runner as disposable and the app scales cleanly by adding more.
What it costs
A small Flask app has a tiny footprint, so it runs for pennies an hour and nothing when it's stopped — usually less than a flat monthly VPS that bills around the clock. See how pricing works or how it compares to a $5 VPS. Hosting a Node.js app follows the same flow, and the general guide to hosting a small always-on app covers the bigger picture.
Put your Flask app online
Free to sign up, billed by the second, no lock-in.