SQLite vs DuckDB vs PostgreSQL in the Browser: A 2026 Benchmark

All three of the major relational engines now ship as WebAssembly builds: sql.js (SQLite), DuckDB-WASM, and PGlite (PostgreSQL). Zro7 uses SQLite for SQLite Browser and DuckDB for the SQL Playground, Big CSV Viewer, and BI Dashboard. Here's how they actually compare in 2026.

SQLite (sql.js)

• Strength: opens existing .sqlite files perfectly. OLTP-shaped (row-oriented, transactional).
• Bundle: ~1.2 MB WASM.
• Best for: inspecting an existing SQLite DB (app data exports, Firefox history, iMessage backups).

DuckDB-WASM

• Strength: columnar + vectorized. Analytical SQL (GROUP BY, joins, window functions) is 10–100× faster than SQLite on large scans.
• Bundle: ~5 MB core + 3 MB extensions loaded on demand.
• Direct file registration: query a CSV or Parquet file without an import step.
• Best for: analytics, CSV/Parquet exploration, BI dashboards, log analysis.

PGlite (PostgreSQL)

• Strength: real Postgres semantics — arrays, JSONB, extensions, triggers.
• Bundle: ~3 MB, tighter than expected because unused Postgres subsystems are stripped.
• Best for: prototyping a Postgres-shaped app without provisioning a server; learning PL/pgSQL locally.

2026 head-to-head numbers

Measured on a 500 MB TPC-H lineitem CSV, MacBook M2, Chrome 128:

• Load CSV → query-ready: DuckDB 1.2s (streamed), SQLite 41s (INSERT loop), PGlite 68s (COPY).
• GROUP BY 8 columns: DuckDB 0.4s, SQLite 22s, PGlite 26s.
• Window fn (running total): DuckDB 0.8s, SQLite 34s, PGlite 30s.
• Startup cold cache: SQLite 0.2s, PGlite 0.4s, DuckDB 0.9s (first query only).

Which should you pick?

1. You have a .sqlite file → SQLite (SQLite Browser).
2. You have CSV / Parquet / JSON and want analytics → DuckDB (SQL Playground).
3. You want to prototype a Postgres-shaped app → PGlite in your own project.