InstantDB

InstantDB — Client-side reactive database with a relational graph model and instant sync. InstantDB puts a real database in the browser and syncs it: queries run locally against a client store, writes apply optimistically, and the server reconciles. The query language, InstaQL, is a nested-object graph syntax rather than SQL, with permissions expressed as rules. It ships auth and file storage, has no server-side function runtime, and is open source though non-trivial to run yourself. Founded 2022. Venture-backed. Open source.

We track it in 1 comparison — Convex alternatives — so every claim below is a cell in a table you can open and check rather than an impression. Across those rosters it sits against 10 other tools, and what follows is where it visibly separates from them.

Where it wins.

• Local-first sync — Yes, which only 3 of 11 tools here manage.
• Agent fit — 4, 2nd of 11.

Each of those is ranked against the whole roster on its category page, not against a hand-picked subset, so a first place here means first of everything we list.

Where it gives ground.

• Entry price — $30 /mo, the weakest of the 9 here. Firebase records $0 /mo.
• Full-text search — No. Convex records Yes.
• Exit cost — 4, 8th of 11. Neon + Drizzle records 1.
• Vector search — No. Convex records Yes.

None of these disqualify it on their own. They are the fields to check against your own requirements before you commit, because they are the ones where a competitor genuinely does better.

Provenance. 22 of 26 tracked fields carry a value for InstantDB, and 10 of those cite a document you can open. Last verified 2026-07-20. Every figure keeps its own provenance — measured by us, claimed by the vendor, inferred, or community-reported — and we would rather print a dash than a guess.

Its nearest neighbour in our data is Appwrite. InstantDB is ahead on Local-first sync (Yes against No) and Optimistic writes (Yes against No). Appwrite takes Cron & scheduling (Yes against No) and Full-text search (Partial against No). That pattern repeats across the rest of the roster — see InstantDB alternatives for the other rivals, each compared the same way.

Founded

2022

Funding

Venture-backed

Licence

Open source

Fields we track

22 of 26

Last verified

2026-07-20

The most pleasant developer experience here for collaborative, instant-feeling UIs, and the smallest API surface. The absence of any server-side function runtime is the constraint people hit, usually around the third feature.

Local-first sync

●Yes1st of 11

Vendor-claimedverified 2026-07-20source

Entry price

$30 /mo9th of 9

Inferredsource

Full-text search

○No9th of 11

Inferred

Exit cost

48th of 11

Inferred

Vector search

○No8th of 11

Inferred

GitHub stars

9,0005th of 10

Inferred

Agent fit

42nd of 11

Inferred

Reactivity

push1st of 11

Vendor-claimedverified 2026-07-20source

InstantDB is the right call in these situations, each one drawn from a field we actually record:

• Multiplayer or collaborative UIs where every interaction must feel local.
• Front-end-heavy teams with no appetite for backend infrastructure.
• Prototypes that need presence, cursors and live editing on day one.
• Local-first sync is your binding constraint. InstantDB records Yes, which only 3 of the 11 tools in the Convex alternatives roster do. We define that field as whether the client keeps a queryable local store that serves reads offline and reconciles with the server on reconnect.
• Agent fit is your binding constraint. InstantDB records 4, 2nd of 11 in the Convex alternatives roster. We define that field as 1–5 judgement score for how far a coding agent can take a feature end-to-end without human plumbing.

Reach for something else when any of the following is a requirement rather than a nice-to-have:

• Entry price. InstantDB records $30 /mo, the weakest of the 9 tools in the Convex alternatives roster. Firebase records $0 /mo on the same field. If that is a hard requirement rather than a preference, start elsewhere.
• Full-text search. InstantDB records No on the Convex alternatives table. Convex records Yes on the same field. If that is a hard requirement rather than a preference, start elsewhere.
• Exit cost. InstantDB records 4, 8th of 11 in the Convex alternatives roster. Neon + Drizzle records 1 on the same field. If that is a hard requirement rather than a preference, start elsewhere.
• Vector search. InstantDB records No on the Convex alternatives table. Convex records Yes on the same field. If that is a hard requirement rather than a preference, start elsewhere.
• Raw SQL. InstantDB records No on the Convex alternatives table. Supabase records Yes on the same field. If that is a hard requirement rather than a preference, start elsewhere.

We publish this block because a comparison that only lists what a tool is good at is marketing. Every figure above sits on the same page as its source, and the field definitions are on the category tables if you want to check how we measured them.

What we don't know. 4 of the 26 fields we track for InstantDB are still blank: Hard limits, Cold start, Function timeout and Egress metered. Those render as dashes rather than as zeroes or assumptions, because an empty cell and a bad cell are not the same thing and only one of them is honest. If you know any of these figures and can point at a document, tell us.