DecentDB vs PGlite: When to Choose Which¶

This document helps developers decide between DecentDB and PGlite for local, embedded, browser, and JavaScript-first database workloads. Both can place a relational database inside an application process, but they optimize for very different ecosystems.

Versions compared: DecentDB 2.15.0 workspace behavior vs public PGlite documentation as of 2026-06-28.

Scope note: PGlite is a WASM build of Postgres packaged as a TypeScript/JavaScript client library. This page compares the product shape and developer fit, not the full PostgreSQL server project.

See also: DecentDB vs SQLite, DecentDB vs DuckDB, SQL Feature Matrix, and SQL Reference.

They Solve the "Local SQL" Problem Differently¶

PGlite and DecentDB are both attractive when a developer wants SQL without running a separate database server. From there, the paths diverge:

• PGlite brings Postgres into JavaScript through WebAssembly. It is strongest when the application is browser/Node/Bun/Deno-centered, when Postgres compatibility matters, or when Postgres extensions such as pgvector or PostGIS are important.
• DecentDB is a Rust-native embedded database with a stable C ABI and maintained bindings. It is strongest when the application needs durable local ACID data, multi-language embedding, branch/diff workflows, local-first sync inspection, policies/masks, and a small standalone engine that is not trying to be Postgres.

The short version:

• Choose PGlite when you want "Postgres inside JavaScript."
• Choose DecentDB when you want "a durable embedded application database with DecentDB-native workflows and bindings."

At a Glance¶

When DecentDB Is the Better Fit¶

1. You need a native embedded database across languages¶

DecentDB exposes one engine through a stable C ABI and maintained language bindings:

• Rust;
• C/C++;
• Python;
• .NET;
• Go;
• Java;
• Node.js;
• Dart;
• Web/WASM surfaces.

That matters when the database has to be the same local data component across desktop, CLI, server, mobile-adjacent, and backend services.

PGlite is intentionally JavaScript/TypeScript-centered. That is a strength when your application is JS-first, but it is a narrower embedding story.

2. You want durable native-file commits by default¶

DecentDB is built around durable local writes. For native files, commits are WAL-backed and fsynced before returning unless the application explicitly selects a relaxed open-time sync mode.

BEGIN;
INSERT INTO audit_log (actor_id, action) VALUES ($1, $2);
COMMIT; -- durable under default native-file settings

PGlite's durability depends on the runtime and filesystem adapter. In browser IndexedDB mode, PGlite documents that the IndexedDB filesystem loads database files into memory and flushes changed files back to IndexedDB; it also offers a relaxed durability mode that returns query results before the flush completes. That can be the right tradeoff for responsive browser apps, but it is a different default risk model than DecentDB's native durable commit path.

3. You want local branch, diff, and guarded restore workflows¶

DecentDB treats snapshots and branches as database workflows:

decentdb snapshot create --db local.ddb --name before-sync
decentdb branch create --db local.ddb --name sync-test --from before-sync
decentdb branch diff --db local.ddb --left main --right sync-test --format json
decentdb branch restore --db local.ddb --branch main --snapshot before-sync --dry-run

PGlite users can use Postgres-compatible dumps, filesystem copies, or application-level versioning. DecentDB's value is that branch/diff/restore are named local database features.

4. You need built-in sync inspection and conflict workflows¶

DecentDB exposes local-first sync state through SQL and CLI:

SELECT * FROM sys_sync_status;
SELECT * FROM sys_sync_journal ORDER BY sequence DESC LIMIT 20;
SELECT * FROM sys_sync_conflicts;
SELECT * FROM sys_sync_retention_report;

PGlite has strong local-first adjacency through Electric sync integrations and live queries. DecentDB's distinction is not "has sync, PGlite does not"; it is that DecentDB stores sync journal, conflict, scope, peer, and retention state as first-class local database surfaces.

5. You need engine-enforced row policies and projection masks¶

DecentDB includes local policy and masking features:

SET AUDIT CONTEXT tenant_id = 'tenant-a';

CREATE POLICY tenant_scope ON invoices
USING tenant_id = current_tenant();

CREATE MASK email_mask ON users(email)
USING left(email, 2) || '***';

PGlite gives you Postgres-style SQL compatibility in an embedded WASM context, but application-level authorization and browser/runtime controls still matter. Choose DecentDB when local policy/mask enforcement is a product requirement.

6. You prefer a small DecentDB SQL surface over full Postgres behavior¶

Full Postgres compatibility is powerful, but it also brings Postgres semantics, types, extension behavior, planner behavior, and migration expectations. DecentDB intentionally exposes a smaller application-focused surface.

SELECT DISTINCT ON (account_id)
       account_id, event_id, created_at
FROM account_events
ORDER BY account_id, created_at DESC;

If you want the embedded database to be simpler than Postgres while retaining useful Postgres-style syntax, DecentDB is the more direct fit.

7. You need deterministic engine-level crash testing hooks¶

DecentDB's engineering posture includes FaultyVFS and WAL failpoint testing for crash and torn-write behavior. This is useful for products where local storage durability is a correctness requirement, not an implementation detail.

PGlite benefits from the PostgreSQL lineage and the surrounding Electric ecosystem, but its WASM and browser persistence behavior should still be tested against the target runtime and filesystem mode.

When PGlite Is the Better Fit¶

1. You want Postgres in the browser or JavaScript runtime¶

This is PGlite's clearest strength:

import { PGlite } from "@electric-sql/pglite";

const db = new PGlite("idb://my-pgdata");
const result = await db.query("select now() as current_time");

If your application is a web app, Electron app, local-first JavaScript app, or Node/Bun/Deno tool that wants Postgres semantics without a separate server, PGlite is specifically built for that experience.

2. You need closer PostgreSQL compatibility¶

If the application already has a Postgres schema, migrations, SQL, types, or ORM stack, PGlite may reduce the dialect gap. Many tools can reason about "Postgres-like" behavior more easily than a new embedded engine.

DecentDB intentionally borrows useful Postgres syntax, but it is not a PostgreSQL server and does not claim full Postgres compatibility.

3. You need Postgres extensions such as pgvector or PostGIS¶

PGlite documents support for many Postgres extensions, including pgvector and PostGIS in its extension surface. That is a major differentiator.

DecentDB currently provides:

• B-tree indexes;
• full-text indexes;
• trigram indexes for substring search;
• expression, partial, and covering-index subsets;
• sandboxed Lua extension packages.

Vector search, geospatial depth, and broader Postgres extension compatibility are future or out-of-scope DecentDB items.

4. You want live queries in a JS UI¶

PGlite's live-query extension lets JavaScript apps subscribe to query results and react when underlying tables change.

That is especially attractive in browser UI frameworks where the database is part of the client-side state model. DecentDB has reactive APIs, but PGlite's JS-first design is a better fit when the UI/runtime ecosystem is the center of the product.

5. You are already building on Electric/PGlite sync¶

PGlite fits naturally with Electric's local-first stack. If your architecture is "cloud Postgres plus local PGlite shape sync," DecentDB would be a different database and sync model rather than a drop-in replacement.

6. You want Postgres development tools and mental models¶

PGlite lets teams reuse Postgres knowledge:

• PostgreSQL SQL dialect expectations;
• extension concepts;
• migration tooling that targets Postgres;
• ORMs with PGlite/Postgres drivers;
• a familiar schema design model for teams already standardized on Postgres.

DecentDB is easier to justify when its native features are part of the product requirements, not when the team simply wants local Postgres.

Side-by-Side Examples¶

Browser-local SQL¶

// PGlite: browser-local Postgres in IndexedDB.
import { PGlite } from "@electric-sql/pglite";

const db = new PGlite("idb://workspace");
await db.exec(`
  CREATE TABLE notes (id serial primary key, body text not null);
  INSERT INTO notes (body) VALUES ('hello from the browser');
`);

Prefer PGlite for a JavaScript-first browser app that wants Postgres semantics and IndexedDB persistence.

Native durable local workflow¶

# DecentDB: native local branch workflow around a durable .ddb file.
decentdb snapshot create --db app.ddb --name before-import
decentdb branch create --db app.ddb --name import-test --from before-import
decentdb branch diff --db app.ddb --left main --right import-test

Prefer DecentDB when branchable local data and conservative native commit durability are central.

Postgres extension dependency¶

-- PGlite/Postgres direction: extension-driven capability.
CREATE EXTENSION vector;
CREATE EXTENSION postgis;

Prefer PGlite when the requirement is compatibility with Postgres extensions. Prefer DecentDB when DecentDB's built-in full-text/trigram indexes, sync surfaces, and policy model are sufficient and simpler.

Summary Decision Matrix¶

Bottom Line¶

Pick PGlite when you want Postgres compatibility inside JavaScript, especially in the browser or in a JS local-first stack.

Pick DecentDB when you want a durable, multi-language embedded application database with DecentDB-native branch, sync, security, and diagnostics workflows.

Neither choice is universally better. PGlite is the more natural local Postgres choice; DecentDB is the more natural durable embedded application database choice.

External References¶

• PGlite documentation
• What is PGlite
• PGlite filesystems
• PGlite live queries
• PGlite extensions
• Electric PGlite sync page