Decision Guide

SQLite vs PostgreSQL: When to Switch (and When to Stay)

Published April 23, 2026 · 10 min read

SQLite powers more applications than any other database on earth. It ships in every iPhone, Android device, and most web browsers. PostgreSQL powers the backends of the world's most demanding SaaS platforms. Choosing between them — or knowing when to migrate from one to the other — is a decision every developer faces. This guide gives you a clear framework for when SQLite is enough, when PostgreSQL becomes necessary, and how to migrate without losing data or sleep.

What SQLite does better than PostgreSQL

SQLite is not a toy database. It is a production-grade, battle-tested embedded engine with distinct advantages:

If your application is a single-node service, a mobile app, a desktop tool, or a small web app with modest concurrency, SQLite is often the right choice. Don't let database fashion pressure you into running PostgreSQL when a file would suffice.

What PostgreSQL does better than SQLite

PostgreSQL is a full-featured client-server relational database with capabilities SQLite simply does not have:

The switching framework: 5 questions

Use these five questions to decide whether you need PostgreSQL or if SQLite is still sufficient:

1. Do you need more than one writer at a time?

SQLite's write concurrency model is simple: one writer, many readers. If your application has multiple processes or threads writing simultaneously, SQLite will serialize them. For low-volume writes, this is fine. For high-volume writes, it becomes a bottleneck.

Rule: If your application has >10 writes per second sustained, or unpredictable write bursts, consider PostgreSQL.

2. Do you need user-level access control?

SQLite has no authentication. File-system permissions are the only security boundary. If your database contains sensitive data and multiple applications or users need different access levels, PostgreSQL's role system is essential.

Rule: If more than one application or user class touches the database, use PostgreSQL.

3. Is your data larger than available RAM?

SQLite performs well when the working set fits in memory. For databases larger than RAM, PostgreSQL's query planner, parallel execution, and sophisticated caching generally outperform SQLite.

Rule: If your database exceeds 50% of available RAM and query performance matters, benchmark PostgreSQL.

4. Do you need advanced querying?

Window functions, common table expressions (CTEs), LATERAL joins, and recursive queries are all fully supported in PostgreSQL. SQLite supports window functions and CTEs, but with limitations. Complex analytical queries are PostgreSQL's strength.

Rule: If you write queries with multiple CTEs, window functions, or recursive logic, use PostgreSQL.

5. Do you need high availability?

SQLite is a single file. If the disk fails, the database is gone unless you have backups. PostgreSQL supports streaming replication, point-in-time recovery, and automatic failover.

Rule: If downtime costs money or reputation, use PostgreSQL with replication.

When to stay on SQLite

Many teams prematurely migrate to PostgreSQL. Here are situations where SQLite is not just acceptable — it is superior:

How to migrate from SQLite to PostgreSQL

If you've answered the five questions and decided to switch, here is a safe migration path:

Step 1: Export SQLite schema

sqlite3 mydb.db ".schema" > sqlite_schema.sql

Step 2: Convert the schema

SQLite and PostgreSQL are closer than MySQL and PostgreSQL, but there are still differences:

SQLite PostgreSQL Notes
INTEGER PRIMARY KEY SERIAL or GENERATED ALWAYS AS IDENTITY SQLite auto-increments on INTEGER PRIMARY KEY
TEXT TEXT Direct equivalent
REAL REAL Direct equivalent
BLOB BYTEA Binary data storage
BOOLEAN BOOLEAN SQLite stores 0/1; PostgreSQL stores true/false
DATETIME TIMESTAMPTZ Always use TIMESTAMPTZ in PostgreSQL
JSON JSONB JSONB is indexed and queryable

Step 3: Compare schemas before migrating data

Paste your SQLite schema and converted PostgreSQL schema into SchemaLens to catch mapping errors before you move a single row. SchemaLens will flag type mismatches, missing constraints, and index differences.

Step 4: Export and import data

# Export SQLite to CSV
sqlite3 -header -csv mydb.db "SELECT * FROM users" > users.csv

# Import into PostgreSQL
psql -d mypostgres -c "COPY users FROM '/path/to/users.csv' WITH (FORMAT csv, HEADER true);"

For larger datasets, use pgloader — a dedicated SQLite-to-PostgreSQL migration tool:

pgloader sqlite:///path/to/mydb.db postgresql:///mypostgres

Step 5: Update application connection strings

Replace SQLite connection logic with PostgreSQL connection pools. Most ORMs (Prisma, Sequelize, SQLAlchemy, Django ORM) make this trivial — just change the connection string dialect.

Step 6: Verify

Run your full test suite against PostgreSQL. Check row counts, constraint behavior, and query results. Performance will differ — some queries will be faster, others slower. Profile before optimizing.

Common migration gotchas

The bottom line

SQLite and PostgreSQL are not competitors. They are tools for different jobs. SQLite is the right default for single-node, low-concurrency applications. PostgreSQL is the right choice for multi-user, high-concurrency, or complex-query workloads.

The mistake is not choosing one or the other. The mistake is refusing to switch when your requirements change. A startup that begins with SQLite and migrates to PostgreSQL at product-market fit is making a smart engineering decision. A startup that runs PostgreSQL from day one for a prototype with ten users is wasting money and complexity.

When you do switch, use SchemaLens to compare your SQLite and PostgreSQL schemas before moving data. Catching a type mismatch or missing constraint in the schema diff stage is infinitely cheaper than debugging data corruption in production.

Compare SQLite and PostgreSQL schemas →

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