Comparison

Google Cloud Spanner vs PostgreSQL

On the evidence we track, PostgreSQL leads this comparison with a composite score of 61/100. Scores are only directly comparable because these tools share a category; the full breakdown and every source is below.

Google Cloud Spanner full profile →PostgreSQL full profile →

Machine formatsMarkdownJSONGraphQLMarkdown is open. JSON and GraphQL need a free key.

Google Cloud Spanner55

★PostgreSQL61

Attribute comparison across 2 tools
Attribute	Google Cloud Spanner	PostgreSQLLeader
vioscaleAI score	55 / 100low · 38%	61 / 100medium · 60%
Pricing
Free tierpricing.free_tier	✓	✓
Modelpricing.model	commercial	open_source
Price levelpricing.price_level	low	free
Integrations
Countintegrations.count	4	6
Security
Disclosure policysecurity.disclosure_policy	-	✓
Scorecardsecurity.scorecard	-	6.1
Trust centersecurity.trust_center	-	https://www.postgresql.org/support/security/faq/2013-04-04/
Vulnerabilitiessecurity.vulnerabilities	-	Count: 0 · Source: https://advisories.ecosyste.ms/api/v1/advisories?ecosystem=helm&package_name=openstack-helm%2Fpostgresql&per_page=100 · Last 12m: 0
Reliability
Sla pctreliability.sla_pct	99.999	-
Status pagereliability.status_page	✓	-
Adoption
Dependent reposadoption.dependent_repos	-	0
Github starsadoption.github_stars	-	22,285
Stackoverflow questionsadoption.stackoverflow_questions	-	170,000
Activity
Commits last 30dactivity.commits_last_30d	-	100
Release
Cadence daysrelease.cadence_days	-	90
License
Spdxlicense.spdx	-	PostgreSQL
Language
Primarylanguage.primary	-	C
Market
Availabilitymarket.availability	-	Available worldwide
Content
Faqcontent.faq	4 items	8 items

Score

vioscaleAI score

Google Cloud Spanner55 / 100low · 38%

PostgreSQL61 / 100medium · 60%

Pricing

Free tier

Google Cloud Spanner✓

PostgreSQL✓

Model

Google Cloud Spannercommercial

PostgreSQLopen_source

Price level

Google Cloud Spannerlow

PostgreSQLfree

Integrations

Count

Google Cloud Spanner4

PostgreSQL6

Security

Disclosure policy

Google Cloud Spanner–

PostgreSQL✓

Scorecard

Google Cloud Spanner–

PostgreSQL6.1

Trust center

Google Cloud Spanner–

PostgreSQLhttps://www.postgresql.org/support/security/faq/2013-04-04/

Vulnerabilities

Google Cloud Spanner–

PostgreSQLCount: 0 · Source: https://advisories.ecosyste.ms/api/v1/advisories?ecosystem=helm&package_name=openstack-helm%2Fpostgresql&per_page=100 · Last 12m: 0

Reliability

Sla pct

Google Cloud Spanner99.999

PostgreSQL–

Status page

Google Cloud Spanner✓

PostgreSQL–

Adoption

Dependent repos

Google Cloud Spanner–

PostgreSQL0

Github stars

Google Cloud Spanner–

PostgreSQL22,285

Stackoverflow questions

Google Cloud Spanner–

PostgreSQL170,000

Activity

Commits last 30d

Google Cloud Spanner–

PostgreSQL100

Release

Cadence days

Google Cloud Spanner–

PostgreSQL90

License

Spdx

Google Cloud Spanner–

PostgreSQLPostgreSQL

Language

Primary

Google Cloud Spanner–

PostgreSQLC

Market

Availability

Google Cloud Spanner–

PostgreSQLAvailable worldwide

Content

Faq

Google Cloud Spanner4 items

PostgreSQL8 items

Capabilities

Feature-by-feature on the axes that matter for relational databases. “-” means undocumented, not absent.

Capability comparison for Relational Databases
Capability	Google Cloud Spanner	PostgreSQL
Core
SQL model	Full SQL	Full SQL
Transactions
ACID transactions	Full	Full
Highest isolation level	Serializable	-
Consistency
Consistency	Strong	-
Scale
Horizontal scale	Natively distributed	Read replicas
Replication
Replication	Consensus (Raft/Paxos)	-
Availability
Automatic failover / HA	✓	✓
Deployment
Deployment	Managed	Self-hosted
Serverless / scale-to-zero	-	✗
Compatibility
Wire compatibility	Postgres protocol	-
Extensibility
Extensions / plugins / UDFs	✓	✓
Licensing
Licence class	Proprietary	Permissive OSS
Data types
JSON / document support	-	✓
Geo / spatial	-	Extension

Core

SQL model

Google Cloud SpannerFull SQL

PostgreSQLFull SQL

Transactions

ACID transactions

Google Cloud SpannerFull

PostgreSQLFull

Highest isolation level

Google Cloud SpannerSerializable

PostgreSQL-

Consistency

Google Cloud SpannerStrong

PostgreSQL-

Scale

Horizontal scale

Google Cloud SpannerNatively distributed

PostgreSQLRead replicas

Replication

Google Cloud SpannerConsensus (Raft/Paxos)

PostgreSQL-

Availability

Automatic failover / HA

Google Cloud Spanner✓

PostgreSQL✓

Deployment

Google Cloud SpannerManaged

PostgreSQLSelf-hosted

Serverless / scale-to-zero

Google Cloud Spanner-

PostgreSQL✗

Compatibility

Wire compatibility

Google Cloud SpannerPostgres protocol

PostgreSQL-

Extensibility

Extensions / plugins / UDFs

Google Cloud Spanner✓

PostgreSQL✓

Licensing

Licence class

Google Cloud SpannerProprietary

PostgreSQLPermissive OSS

Data types

JSON / document support

Google Cloud Spanner-

PostgreSQL✓

Geo / spatial

Google Cloud Spanner-

PostgreSQLExtension

What each one is

The product in its own terms, so the numbers below have context.

Google Cloud Spanner

Google Cloud Spanner is a managed database service that unifies multiple data models (relational, key-value, graph, vector search) on one platform. It provides up to 99.999% uptime with globally consistent transactions through a distributed timestamp system.

Independently observed

PostgreSQL

Leader

PostgreSQL is an open source relational database with over 35 years of active development. It supports transactions, user-defined functions, and a broad subset of SQL, widely used for data storage and retrieval in applications ranging from small projects to enterprise deployments.

Independently observed

Pricing

List pricing as published by each vendor, with the date we read it. Always verify at the source before you buy.

Google Cloud Spanner

Usage-basedFree tier90-day trial

Usage-based pricing: compute capacity (nodes/processing units, hourly), storage (monthly), backups, data replication, network bandwidth. Free 90-day trial instances. Optional 1-year and 3-year committed use discounts. Three editions available: Standard, Enterprise, and Enterprise Plus.

as of 2026-08-03verify ↗

PostgreSQL

Leader

Open sourceFree tier

as of 2026-08-14verify ↗

Platform & deployment

Where each product runs and how it can be hosted. A dash means undocumented, not unsupported.

Platform and deployment support comparison
Supports	Google Cloud Spanner	PostgreSQL
macOSPlatforms	-	✓
WindowsPlatforms	-	✓
LinuxPlatforms	-	✓
Cloud / SaaSDeployment	✓	✓
Self-hostedDeployment	✓	✓
On-premiseDeployment	✓	✗
HybridDeployment	✓	✗

Platforms

macOS

Google Cloud Spanner–

PostgreSQL✓

Windows

Google Cloud Spanner–

PostgreSQL✓

Linux

Google Cloud Spanner–

PostgreSQL✓

Deployment

Cloud / SaaS

Google Cloud Spanner✓

PostgreSQL✓

Self-hosted

Google Cloud Spanner✓

PostgreSQL✓

On-premise

Google Cloud Spanner✓

PostgreSQL✗

Hybrid

Google Cloud Spanner✓

PostgreSQL✗

Integrations

What each product connects to. Counts come from the vendor's own integration directory where one exists.

Google Cloud Spanner

9 total

Gemini Enterprise Agent Platform
Gemini CLI
Model Context Protocol (MCP)
Agent Development Kit (ADK)
Data Agent Kit
VS Code
Cursor
GitHub Copilot
Kiro

Independently observed

PostgreSQL

Leader

10 total

CloudNativePG
Kubernetes
Patroni
pgAdmin
pgVector
PostGIS
pgAudit
Spock
Cilium
Submariner

Independently observed

Still deciding?

Google Cloud Spanner or PostgreSQL: which one depends on you

A composite score cannot know your constraints. Describe them and both get re-weighted against what you actually need, with the evidence behind every position.

Free to run, no account needed to start. How the evaluation works

Comparison generated from independently-sourced facts. Every value links to its source and retrieval date. See the method.