BRAT

At a glance

• Editor score
  7.2 / 10
• Pricing
  Open source
• Best for
  Researchers annotating complex text structures
• Paid from
  Free
• Supported modalities
  text
• Facts checked
  22 Sep 2026

• Where it wins

  • Supports spans, relations, events, attributes, and equivalence annotations
  • Enables collaborative editing and comparison across annotation sets
  • Connects external annotation services and exports to multiple formats

• Where it doesn't

  • Focused on text rather than multimodal labeling
  • Self-hosted deployment requires a locally installed server
  • Its research-oriented scope may not suit broad labeling programs

Our verdict on BRAT

BRAT is an open-source, browser-based tool for structured annotation of text documents. It is designed for researchers and teams working on natural-language processing, corpus development, information extraction, and related workflows. Its annotation model covers text spans, binary relations, events, attributes, and equivalence annotations, while configurable annotation types and constraints support custom schemes. Human review and model-assisted labeling are supported through collaborative annotation and external automatic annotation web services.

The product’s main strength is depth within structured text annotation. Multiple annotators can work through a server-coordinated workflow, compare annotation sets, and search or concordance across documents and collections. BRAT also supports document collection import and export, with output formats including standoff, SVG, PNG, PDF, and EPS. Integrations with external annotation web services, Freebase, Wikipedia, and Open Biomedical Ontologies extend its fit for research datasets and knowledge-oriented projects.

BRAT is self-hosted, so teams install the server locally rather than selecting among hosted subscription tiers. That deployment model can suit organizations that want control over their annotation environment, but it places setup responsibility on the team. The product’s focus is intentionally narrow: it is built around text and structured linguistic or semantic annotation, not a broad set of labeling modalities. Choose BRAT when complex text relationships, customizable annotation schemes, collection-level search, and research workflows matter most. Teams seeking image, audio, or video labeling, or a broader commercial data-labeling platform, should consider a different category fit.

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BRAT pricing

BRAT fact sheet

BRAT integrations

BRAT lists 4 integrations on its own site.

• External annotation web services
• Freebase
• Wikipedia
• Open Biomedical Ontologies

Alternatives to BRAT

• Label StudioA flexible open-source labeling platform with broad annotation, export, and deployment options.9.3
• CVATA broad annotation toolkit with free access, AI assistance, collaboration, and self-hosting.9.2
• ArgillaA free, open-source labeling workspace with strong text and image support.9.0

See all BRAT alternatives →

Featured on iTechGuides

BRAT is listed in our AI Data Labeling Tools directory. Add the badge to your site — it links back to this page.

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Reviewed by iTechGuides Editors · Editorial team · Updated Oct 2026

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Last updated 7 Oct 2026 · How we research and update