Best Free Document Databases

a fast and straightforward NoSQL cloud database service. With restdb.io you get schema, relations, automatic REST API (with MongoDB-like queries), and an efficient multi-user admin UI for working with data. The free plan allows 3 users, 2500 records, and 1 API request per second. The page we cite for restdb.io states in words that it is free, which confirms the price — the limits stated here come from our own record rather than from that page.

Listed in Databases, and on this page because we labelled it document. We read that on 2026-08-31 from https://restdb.io/, where it says: “Simple online NoSQL database backend with automatic APIs and low code JavaScript hooks”. How we use this

Multi-model cloud database — The 'Start' plan offers 1GB of storage free, forever, and a free compute instance with 0.25 vCPU and 1 GB memory ($0.000/hr). Further instances are available from $0.021/hr.

Listed in Databases, and on this page because we labelled it document. We read that on 2026-08-31 from https://surrealdb.com/, where it says: “SurrealDB is a database and an agent memory layer. Documents, graphs, vectors, and SQL in one engine - and context for your AI agents wherever your data lives.”. How we use this

Spark plan, no payment method needed: Auth (50K MAU), Firestore Standard edition (1 GiB stored, 50K reads/day, 20K writes/day, 20K deletes/day), Realtime Database (100 simultaneous connections, 1 GB stored, 10 GB/month downloaded), Hosting (10 GB storage, 360 MB/day transfer), and no-cost Analytics, Crashlytics and Cloud Messaging. Firestore Enterprise on Spark includes 1 GiB stored, 10 GiB/month network egress, 40K write units/day, 50K read units/day, 50K real-time update units/day. Cloud Functions and Cloud Storage need the Blaze plan. Note — 2026-12-01: Firebase Spark projects that enabled Remote Config before September 1, 2026 can use it under the old terms until December 1, 2026. From December 1, 2026, the 100,000-fetches-a-day limit applies to them, with 30 days of full service from the first day they go over, then throttling unless they upgrade to Blaze. A Spark project that upgrades to Blaze before November 15, 2026 is not billed for Remote Config until February 1, 2027. Blaze projects from before September 1, 2026 start Remote Config billing on February 1, 2027. Source ↗

• If a Spark project exceeds a no-cost quota, that product is shut off for the project (all its apps) for the rest of the calendar month, unless you upgrade to Blaze. (From firebase.google.com/docs/projects/billing/firebase-pricing-plans, read 2026-10-05.)
• A Spark account can create a small number of projects, usually about 5-10. (From firebase.google.com/support/faq, read 2026-10-05.)
• Linking a Cloud Billing account to a Spark project, including one with $300 Google Cloud free trial credits, automatically upgrades it to the pay-as-you-go Blaze plan. (From firebase.google.com/docs/projects/billing/firebase-pricing-plans, read 2026-10-05.)
• On Spark, email-link sign-in is limited to 5 emails a day; sending more needs a billing account (Blaze). (From firebase.google.com/docs/auth/limits, read 2026-10-07.)
• Phone (SMS) sign-in is not available on the Spark plan; on Blaze each SMS sent is billed. (From firebase.google.com/pricing, read 2026-10-20.)
• Since September 1, 2026, Remote Config allows up to 100,000 fetch requests a day per Spark project at no cost. A Spark project that exceeds this limit gets 30 days of normal service, then is throttled unless it upgrades to Blaze. Blaze projects pay $0.06 per 10,000 requests above 100,000 a day, up to 10,000,000, and $0.01 per 10,000 above that. (From firebase.google.com/docs/remote-config/pricing, read 2026-10-17.)
• Spark projects that used Remote Config before September 1, 2026 are subject to the 100,000-fetches-a-day limit from December 1, 2026 until they upgrade to Blaze. Blaze projects that used Remote Config before September 1, 2026 start Remote Config billing on February 1, 2027. A Spark project that used Remote Config before September 1, 2026 and upgrades to Blaze before November 15, 2026 starts Remote Config billing on February 1, 2027. (From firebase.google.com/docs/remote-config/pricing, read 2026-10-17.)
• On the Blaze plan, all Gemini Developer API usage, including calls through Firebase AI Logic, is pay-as-you-go, and most projects must prepay. A project with no billing account (on Spark) can use the Gemini Developer API's free tier with no payment method. (From firebase.google.com/docs/ai-logic/pricing, read 2026-10-21.)
• From November 2, 2026, Firebase AI Logic requires App Check enforcement. (From firebase.google.com/docs/ai-logic/pricing, read 2026-10-21.)
• Firebase's Spark plan needs no credit card or other payment method. (From firebase.google.com/pricing, read 2026-10-22.)

Listed in Databases, and on this page because we labelled it document. We read that on 2026-08-31 from https://firebase.google.com/docs/firestore, where it says: “Use the flexible, scalable NoSQL cloud database from Google Cloud to store and sync data for client and server-side development.”. How we use this

filess.io is a platform where you can create two databases with up to 10 MB per database of the following DBMS for free: MySQL, MariaDB, MongoDB, and PostgreSQL.

Listed in Databases, and on this page because we labelled it document. We read that on 2026-08-31 from https://filess.io, where it says: “Ship your full stack apps in seconds. Web Hosting, Managed Databases (MySQL, PostgreSQL, MongoDB, MariaDB & SQL Server) and Secure Tunnels.”. How we use this

Free 512 MB shared cluster (M0), always free, available on AWS/Azure/GCP. Includes Atlas Vector Search for AI/RAG applications

• Atlas automatically pauses Free (M0) clusters after 30 days of inactivity where there are zero connections to the cluster. (From mongodb.com/docs/atlas/reference/free-shared-limitations, read 2026-10-18.)
• A Free cluster allows at most 500 connections and 100 read and write operations per second; operations over that limit are queued. (From mongodb.com/docs/atlas/reference/free-shared-limitations, read 2026-10-18.)
• MongoDB Atlas's free M0 cluster needs no credit card. (From mongodb.com/resources/basics/databases/cloud-databases/free-cloud-database, read 2026-10-22.)
• An agent can create a MongoDB Atlas M0 cluster via the API without an account. A person must sign in to claim the cluster, which then becomes a standard Free cluster with no expiration. Unclaimed clusters pause after 2 days and delete after 7. (From mongodb.com/docs/atlas/tutorial/create-ephemeral-cluster, read 2026-10-22.)
• The Flex tier has a monthly base price of $8.00, which includes 5GB storage, 100 operations per second and unlimited data transfer. More operations per second cost extra by tier, and Flex clusters are capped at $30 per month. (From mongodb.com/docs/atlas/billing/atlas-flex-costs, read 2026-10-29.)
• Flex clusters limit total data storage to 5 GB and the number of read and write operations to 500 operations per second. (From mongodb.com/docs/atlas/reference/flex-limitations, read 2026-10-29.)
• Upgrading a Free cluster asks for payment information and starts billing. Changing from a Free cluster to a Flex cluster requires downtime. (From mongodb.com/docs/atlas/scale-cluster, read 2026-10-29.)

Listed in Databases, and on this page because we labelled it document. We read that on 2026-08-31 from https://www.mongodb.com/products/platform/atlas-database, where it says: “Find out how the document model eliminates operational complexity while ensuring unmatched resilience, scalability, and enterprise-grade security through the Atlas cloud database.”. How we use this