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Developer Tools · head to head

CodeSandbox vs Convex

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CodeSandbox

Developer Tools

Cloud platform for instant, isolated development sandboxes and code execution

From
Free
Free plan
Yes
Visit CodeSandboxFull review
Convex logo

Convex

Databases

Reactive backend combining a document database, TypeScript server functions and live queries, source-available under the Functional Source Licence.

From
Free
Free plan
Yes
Visit ConvexFull review

The short version

  • CodeSandbox is free; Convex starts at $25/mo.
  • Only CodeSandbox lists instant sandboxes; only Convex lists reactive queries.
  • Where CodeSandbox falls short: public sandboxes are visible to others by default, which is not ideal for proprietary code.
  • Prices and features on this page were last checked on 13 November 2026.

Where they differ

Only the attributes on which CodeSandbox and Convex actually diverge.

Attributes where CodeSandbox and Convex differ
AttributeCodeSandboxConvex
Pricing modelFreemiumSubscription
PlatformsWeb, APIWeb
CategoryDeveloper ToolsDatabases

Identical on both: starting price (Free), free tier (Yes).

What each one covers

Drawn from each product's published feature list. An absence here means we hold no record of it - not that the product lacks it.

Only in CodeSandbox

  • Instant sandboxes
  • Programmatic sandbox API
  • Secure isolated execution
  • Browser-based editor
  • CI/CD sandbox support
  • Scalable VM infrastructure

Only in Convex

  • Reactive queries
  • TypeScript server functions
  • ACID transactions
  • Document database
  • Scheduling and workflows
  • File storage
  • Text and vector search
  • End-to-end types

What people use each for

The jobs each tool is most often brought in to do.

CodeSandbox

  • Running AI agent-generated code safely in isolationnot Convex
  • Prototyping and sharing web projects in-browsernot Convex
  • Executing untrusted code for a code playground productnot Convex
  • Using sandboxes as ephemeral CI/CD build environmentsnot Convex

Convex

  • Collaborative applications where several users see the same data and every client must reflect a change immediatelynot CodeSandbox
  • Agent backends that need durable state, scheduled work and transactional writes without assembling a queue, a database and a cachenot CodeSandbox
  • Small product teams who need a complete backend, including auth integration, file storage and subscriptions, without hiring infrastructure engineersnot CodeSandbox
  • Prototypes that must become production without a rewrite of the data layer, where end-to-end TypeScript types remove a class of integration bugsnot CodeSandbox

Where each one falls short

Documented limitations, not opinions. Every one is a constraint you would hit in normal use.

CodeSandbox

  • Focus has shifted toward programmatic sandbox infrastructure, which may be less approachable for casual users just wanting a quick online editor
  • Public sandboxes are visible to others by default, which is not ideal for proprietary code

Convex

  • The Functional Source Licence is not an OSI open source licence: competing use is prohibited until each release reaches its second anniversary and converts to Apache 2.0, so you may self-host but you may not build a service on it
  • Transactions are bounded at one second of user code, 16 MiB read and written, 32,000 documents scanned and 16,000 written, so every backfill, migration or bulk import has to be chunked into scheduled batches rather than written as a single operation
  • There is no SQL and no query planner; you declare up to 32 indexes per table and traverse them, and joins are loops in TypeScript, so an unanticipated access pattern requires a schema and index change rather than a new query
  • It is not an analytical database, so reporting means streaming data out to a warehouse and BI tools cannot be pointed at Convex directly, which adds a pipeline the architecture diagram did not originally include
  • The application is written against Convex's function and client APIs rather than a standard protocol, so leaving means rewriting the data access layer and replacing the reactivity model, not repointing a connection string

Pricing, plan by plan

CodeSandbox

Free
  • FreeFree
    • Public sandboxes
    • Basic sandbox usage

Convex

Free
  • Free & StarterFree
    • Supports 1-6 developers
    • Reactive database
    • File storage
  • Professional$25
    • Supports up to 20 developers
    • All Starter features
    • Log streaming
  • Business & Enterprise$2,500/month minimum
    • Supports 50+ developers
    • SAML/SSO
    • Service SLAs

Which should you pick?

Choose CodeSandbox if

  • You need instant sandboxes.
  • You want to start without paying.
  • You work on Web, API.
  • You also want programmatic sandbox api.
CodeSandbox review

Choose Convex if

  • You need reactive queries.
  • You want to start without paying.
  • You also want typescript server functions.
Convex review

Questions people ask

Is CodeSandbox or Convex better?
Neither clearly leads. CodeSandbox starts at Free and Convex at Free, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
Which is cheaper, CodeSandbox or Convex?
CodeSandbox starts at Free and Convex at Free.
Does CodeSandbox or Convex run on more platforms?
CodeSandbox runs on Web, API. Convex runs on Web.
Can I use CodeSandbox for free?
Both have a free tier, so you can try either at no cost before committing.
What is CodeSandbox best used for?
CodeSandbox is most often used for running ai agent-generated code safely in isolation, prototyping and sharing web projects in-browser, executing untrusted code for a code playground product, using sandboxes as ephemeral ci/cd build environments. Of those, running ai agent-generated code safely in isolation and prototyping and sharing web projects in-browser are not what Convex is typically brought in for.
What can CodeSandbox do that Convex cannot?
CodeSandbox covers Instant sandboxes, Programmatic sandbox API, Secure isolated execution, Browser-based editor. Convex covers Reactive queries, TypeScript server functions, ACID transactions, Document database.

Answered from the vendors’ own pages

CodeSandbox: Does CodeSandbox offer a free tier?

Yes, CodeSandbox offers a free option available on the platform. Users can start for free.

Source
Convex: Is Convex open source?

It is source-available under FSL-1.1-Apache-2.0. You may read, modify and self-host it, but competing use is prohibited until each release converts to Apache 2.0 on its second anniversary.

CodeSandbox: Where can I find CodeSandbox's pricing details?

CodeSandbox maintains a dedicated pricing page, but specific tier names, feature breakdowns, and costs are not displayed on the landing page.

Source
Convex: Can I self-host it?

Yes. The backend, dashboard and CLI can run on your own infrastructure, with most of the features of the cloud product. Self-hosted instances include a telemetry beacon that can be disabled.

Convex: Does it support SQL?

No. Data is accessed through a TypeScript query builder over declared indexes. Relationships are traversed in code, which is explicit and type-safe but means no ad hoc querying.

Convex: What happens if a mutation exceeds the limits?

It fails rather than running longer, so bulk work must be split into batches and scheduled. The limits are per transaction: one second of user code, 16 MiB read and written, 32,000 documents scanned and 16,000 written.

Convex: How does reactivity actually work?

Queries are deterministic functions and Convex records the data each one read. When a mutation changes that data, affected queries are re-run and subscribed clients receive the new result, so cache invalidation is handled by the platform.

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