Turso replicates SQLite so reads are local and writes cross the wire

Turso's pitch compresses to one asymmetry: it takes SQLite — a local, in-process database — and replicates it, so reads happen at local-SQLite speed from a nearby replica while writes travel to the primary.

That asymmetry decides what it's for. Read-heavy workloads (content sites, catalogs, feature flags, per-user config) get microsecond-class reads worldwide with a generous free allowance. Write-heavy workloads inherit cross-region write latency on every insert — the one thing SQLite was never asked to do — and fight the model.

It also explains the embedded-replica trick: sync a full copy into your app's filesystem and reads don't even leave the process; the network exists only for sync and writes. That's a deployment shape Postgres services can't offer at all.

Free-tier numbers and where the write path starts to hurt: https://toolfreebie.com/turso-free-sqlite-database/