Apache IoTDB vs QuestDB

Apache IoTDB9.3Visit QuestDB8.4Visit

Higher score Apache IoTDB #1 in Time-Series Databases 9.3/10 Open source ✓ 3 of 3 features Visit Apache IoTDB

vs

QuestDB #9 in Time-Series Databases 8.4/10 Free plan Free plan✓ 3 of 3 features Visit QuestDB

• Apache IoTDB fits best

  IoT data with SQL and many ingestion options

• QuestDB fits best

  Open-source SQL time-series deployments

Advertiser disclosure: iTechGuides is reader-supported. Vendors can pay for top positions in our rankings and for a place on other products' pages, and we may earn a commission when you click some links. Bought places stand at the number bought; this page and our disclosure say so. Paying vendors may get a fuller, more detailed review from our editors, and that review can change their score. How we rank.

Side by side

Feature	Apache IoTDB 9.3/10 Visit ↗	QuestDB 8.4/10 Visit ↗
At a glance
Editor score	9.3	8.4
Ranking	#1 in Time-Series Databases	#9 in Time-Series Databases
Best for	IoT data with SQL and many ingestion options	Open-source SQL time-series deployments
Pricing model	Free	Free
Starting price	Open source	Free plan
Free plan	Not checked yet	✓ (best)
Free trial	—	—
Deployment	Cloud, Self-hosted, Desktop	Cloud, Self-hosted, Browser extension
Platforms	Web, Windows, Linux	Web, Windows, macOS, Linux
Support	Community, Docs	Email, Community, Docs
Integrations	4 integrations	11 integrations
Built for	Small business, Mid-market, Enterprise	Small business, Mid-market, Enterprise
Features Apache IoTDB 3/3 · QuestDB 3/3
SQL support	✓	✓
Retention policies	✓	✓
Horizontal scaling	✓	✓
Specs
Deployment	Both	Both
Query languages	IoTDB-SQL; Tree Mode SQL; Table Mode SQL	QuestDB SQL, PostgreSQL wire protocol, REST API, Apache Parquet
Ingestion methods	INSERT SQL; Java JDBC; Java, C++, Python, and Go native APIs; REST API; MQTT; CSV; TsFile	QuestDB Wire Protocol, InfluxDB Line Protocol, REST API, native client libraries, SQL INSERT, Kafka connector, CSV import
Our review
Pros	High-throughput real-time and batch ingestion across multiple interfaces SQL with tree and table models, filtering, aggregation, and grouping TTL retention, cluster scaling, and broad analytics integrations	Apache 2.0 core with self-managed deployment SQL extensions, retention policies, and materialized views Integrates with Kafka, Grafana, Spark, and Parquet
Cons	Self-managed deployment places operations and maintenance on the organization Uses IoTDB SQL dialects rather than a single conventional SQL model Its broad ingestion and integration surface may exceed smaller IoT projects	High availability and replication are Enterprise features Enterprise pricing is contact-based Self-managed deployment requires infrastructure ownership
Our verdict	Apache IoTDB is an open-source, IoT-native time-series database for organizations managing large volumes of device and sensor data. It suits industrial use cases across energy, transportation, aerospace, manufacturing, and general IoT… Read the review →	QuestDB is an open-source time-series database for financial market data, telemetry, and real-time analytics. It is aimed at teams that want SQL alongside time-series capabilities, with a column-oriented, time-partitioned storage engine… Read the review →

Strengths and trade-offs

• Apache IoTDB — where it wins

  • High-throughput real-time and batch ingestion across multiple interfaces
  • SQL with tree and table models, filtering, aggregation, and grouping
  • TTL retention, cluster scaling, and broad analytics integrations

  Where it doesn't

  • Self-managed deployment places operations and maintenance on the organization
  • Uses IoTDB SQL dialects rather than a single conventional SQL model
  • Its broad ingestion and integration surface may exceed smaller IoT projects

• QuestDB — where it wins

  • Apache 2.0 core with self-managed deployment
  • SQL extensions, retention policies, and materialized views
  • Integrates with Kafka, Grafana, Spark, and Parquet

  Where it doesn't

  • High availability and replication are Enterprise features
  • Enterprise pricing is contact-based
  • Self-managed deployment requires infrastructure ownership

• Apache IoTDB9.3/10 · Open source

  A focused open-source choice for high-volume IoT ingestion, SQL, retention, and scaling.

  Visit Apache IoTDBFull verdict →
• QuestDB8.4/10 · Free plan

  A strong fit for teams wanting SQL, flexible ingestion, and self-managed time-series infrastructure.

  Visit QuestDBFull verdict →