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Deno vs Firebase Realtime Database

Deno logo

Deno

Developer Tools

A fast, open-source, fully Node-compatible JS runtime with TypeScript baked right in

From
Free
Free plan
Yes
Visit DenoFull review
Firebase Realtime Database logo

Firebase Realtime Database

Databases

Store and sync data in real-time across all clients

From
Free
Free plan
Yes
Visit Firebase Realtime DatabaseFull review

The short version

  • Firebase Realtime Database is a cloud-hosted NoSQL database.
  • Free plans on both; paid from $20/mo and $5/mo.
  • Where Deno falls short: egress bandwidth overage costs $0.20/GB which can become expensive for high-traffic applications.
  • Where Firebase Realtime Database falls short: the no-cost Spark plan caps storage at 1 GB, downloads at 10 GB per month and simultaneous connections at 100.
  • Prices and features on this page were last checked on 13 November 2026.

Where they differ

Only the attributes on which Deno and Firebase Realtime Database actually diverge.

Attributes where Deno and Firebase Realtime Database differ
AttributeDenoFirebase Realtime Database
PlatformsWebWeb, iOS, Android
CategoryDeveloper ToolsDatabases

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

Not yet recorded: founded for Deno.

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 Deno

Nothing recorded that Firebase Realtime Database does not also cover.

Only in Firebase Realtime Database

  • Real-time Sync
  • Offline Support
  • JSON Storage
  • Security Rules
  • Data Validation
  • Multi-platform SDKs
  • Scalable
  • Firebase Auth

What people use each for

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

Deno

  • Running TypeScript natively without transpilation overheadnot Firebase Realtime Database
  • Migrating Node.js applications to secure-by-default runtimenot Firebase Realtime Database
  • Deploying edge functions and serverless containers seamlesslynot Firebase Realtime Database
  • Consolidating developer tools into single binarynot Firebase Realtime Database

Firebase Realtime Database

  • Syncing JSON application state between clients in real timenot Deno
  • Backing mobile and web apps with offline capable data storagenot Deno
  • Prototyping realtime features such as presence and chatnot Deno

Where each one falls short

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

Deno

  • Egress bandwidth overage costs $0.20/GB which can become expensive for high-traffic applications
  • CPU time overage is $0.10/hour on Pro and Builder tiers, adding to costs for compute-intensive workloads
  • Enterprise pricing is not disclosed; requires sales contact

Firebase Realtime Database

  • The no-cost Spark plan caps storage at 1 GB, downloads at 10 GB per month and simultaneous connections at 100
  • The Spark plan does not support multiple databases in a project
  • Even on the paid Blaze plan simultaneous connections are capped at 200,000 per database
  • Billing is by data transferred out at $1 per GB plus $5 per GB stored, so chatty clients cost more than the data volume suggests

Pricing, plan by plan

Deno

Free
  • FreeFree
    • 1 million requests/month
    • 20GB egress bandwidth
    • 10 apps
  • Pro$20/mo
    • 5 million requests/month
    • 200GB egress
    • 50 apps
  • Builder$200/mo
    • 25 million requests/month
    • 2,000GB egress
    • 10,000 apps
  • EnterpriseOn request
    • Custom limits on all metrics
    • 99.95% reliability SLA
    • Email support with SLA

Firebase Realtime Database

Free
  • SparkFree
    • 1 GB data storage included
    • 10 GB per month data downloads included
    • No charges for usage within limits
  • Blaze$5
    • Maintains Spark free allowances
    • Pay-as-you-go for usage exceeding limits
    • Billing applies to data stored and outbound network traffic

Which should you pick?

Choose Deno if

  • You want to start without paying.
Deno review

Choose Firebase Realtime Database if

  • You need real-time sync.
  • You want to start without paying.
  • You work on Web, iOS, Android.
  • You also want offline support.
Firebase Realtime Database review

Questions people ask

Is Deno or Firebase Realtime Database better?
Neither clearly leads. Deno starts at Free and Firebase Realtime Database at Free, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
Which is cheaper, Deno or Firebase Realtime Database?
Deno starts at Free and Firebase Realtime Database at Free.
Does Deno or Firebase Realtime Database run on more platforms?
Deno runs on Web. Firebase Realtime Database runs on Web, iOS, Android.
Can I use Deno for free?
Both have a free tier, so you can try either at no cost before committing.
What is Deno best used for?
Deno is most often used for running typescript natively without transpilation overhead, migrating node.js applications to secure-by-default runtime, deploying edge functions and serverless containers seamlessly, consolidating developer tools into single binary. Of those, running typescript natively without transpilation overhead and migrating node.js applications to secure-by-default runtime are not what Firebase Realtime Database is typically brought in for.
What can Deno do that Firebase Realtime Database cannot?
Firebase Realtime Database covers Real-time Sync, Offline Support, JSON Storage, Security Rules.

Answered from the vendors’ own pages

Deno: How much does Deno Deploy cost?

Deno Deploy offers a free tier at $0/month, Pro at $20/month, and Builder at $200/month. Enterprise has custom pricing. All plans include base request and bandwidth limits, with overage charges for additional usage.

Source
Firebase Realtime Database: How much does Firebase Realtime Database cost?

Firebase Realtime Database offers a free Spark plan (1 GB storage, 10 GB/month downloads) and a pay-as-you-go Blaze plan. On Blaze, storage costs $5 per GB per month, evaluated daily, with no monthly minimum charges.

Source
Deno: What are Deno Deploy's overage charges?

Egress bandwidth overages cost $0.20 per GB. CPU time overages are $0.10 per hour on Pro and Builder tiers. Memory time and KV database operations also incur charges beyond included limits.

Source
Firebase Realtime Database: What is included in Firebase Realtime Database free tier?

The Spark plan includes 1 GB of data storage and 10 GB per month of data downloads at no cost. Usage within these limits incurs no charges, making it suitable for small projects and testing.

Source
Deno: How many apps can I deploy on Deno's free plan?

The free tier includes 10 apps with up to 1 concurrent build. Pro tier supports 50 apps with 3 concurrent builds, and Builder supports 10,000 apps with 20 concurrent builds.

Source
Firebase Realtime Database: Does Firebase Realtime Database charge for denied or rejected operations?

Yes. Firebase charges for all traffic to and from the database on the Blaze plan, including operations denied by security rules, outbound network traffic at the session layer, and connection and encryption overhead from all operations.

Source
Deno: How many team members can access Deno Deploy?

The free tier supports up to 3 team members. Pro supports 10 team members. Builder supports 25 team members. Enterprise has custom seat limits.

Source
Firebase Realtime Database: Can I set a spending limit on Firebase Realtime Database?

Firebase offers budget alerts but does not cap spending automatically. Users must monitor their usage dashboard in the Firebase console to track connections, storage, downloads, and load metrics; a calculator is available for cost estimation.

Source
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