Fess
- Android app
- Not listed
- Free plan
- Yes
- Runs on
- api, Linux, Mac, self-hosted, Web, Windows

Summary
Fess is an open-source enterprise search server for finding information across websites, files, and databases. It includes a crawler, indexer, administration console, and search interface, and is built on OpenSearch. The crawler can access web pages, file systems, Windows shared folders, and databases. Supported formats include Microsoft Office documents and PDFs, with external text extraction such as OCR available. Search tools include facets, drill-down, autocomplete, suggestions, cached results, and thumbnails. Secure search supports BASIC, DIGEST, NTLM, and FORM authentication, as well as single sign-on methods including Active Directory and SAML. Fess can return results in JSON, connect to websites through JavaScript, and extend functionality with plugins. Documentation covers an API, and external systems can use access tokens. Fess runs on systems with a Java or Docker runtime. The Apache-licensed software is free for personal and commercial use, but its open-source edition is community-supported without guaranteed support; paid professional support is available by email. The downloads page lists Fess 15.8.0 with Java 21 and OpenSearch 3.8.0 as the latest stable release.
Who it is for
Fess suits organizations that want to run their own search across websites, file stores, and databases. It can also suit personal or commercial users comfortable with community support or a paid support option.
What is good
- Searches websites, files, and databases.
- Includes crawling, indexing, administration, and search tools.
- Supports common authentication methods and single sign-on.
- Apache-licensed for free personal and commercial use.
- Results can be returned in JSON.
What to know first
- Open-source edition has no guaranteed support.
- Running it requires a Java or Docker runtime.
- Paid professional support pricing is not listed.
Everything Xiaomi review
Fess: the full review
Fess offers a broad set of search and authentication features in a self-hosted, Apache-licensed package. Organizations that require guaranteed response should consider its paid email support rather than relying on community support.
Overview
Fess is a self-hosted search server for organizations that need one search experience across websites, files and databases. It suits teams prepared to manage software on Java or Docker, especially when access controls and customizable integration matter. Its broad search and authentication toolkit is compelling at no license cost, but community support carries no guaranteed response.
Key features
Fess brings crawling, indexing, administration and the search interface into one system built on OpenSearch. Its crawler reaches web pages, file systems, Windows shared folders and databases, and can index Office documents and PDFs; external text extraction such as OCR can extend coverage. That range makes Fess useful for mixed repositories, though the self-hosted model means the organization must provide and operate the runtime.
Searchers can narrow results with facets and drill-down, while autocomplete, suggestions, cached results and thumbnails help users find and assess material. Secure search supports BASIC, DIGEST, NTLM and FORM authentication, as well as single sign-on through Active Directory, SAML and other methods. Permission synchronization is supported, an important distinction for organizations that cannot expose a shared index without respecting source access.
For integration, Fess can return JSON, connect to websites through JavaScript, and extend functionality with plugins. Its documentation covers an API, and access tokens can be used for external-system integration. These options make it adaptable, but organizations should expect to own the deployment and integration work.
Pricing
Fess Open Source — 0.00 USD per free. The Apache-licensed edition is free for personal and commercial use, with community support and no guaranteed response. It is the natural fit for organizations with the technical capacity to run and maintain a self-hosted search service.
Professional Support — custom pricing. Email support is priced per site. Silver includes 5 incidents/3 months and a first-response target of three business days; Gold includes 10 incidents/3 months with a two-business-day target; Platinum offers unlimited incidents and a one-business-day target. Organizations that need a defined support path can choose a tier, while teams comfortable relying on the community can avoid support fees.
Platforms
Fess is self-hosted and runs on operating systems with a Java or Docker runtime. Its listed platforms include Linux, macOS, Windows, web and API; it is not a hosted search service.
Who it's for
Fess is best suited to organizations that need to search across varied internal and public content, require authentication and permission-aware access, and can handle self-hosting. It is less suitable for teams that need guaranteed help without purchasing professional support or that want a managed service rather than operating their own deployment.
Pros and cons
- Pro: Broad crawler coverage, including databases, Windows shares and common office documents, helps consolidate search across unlike repositories.
- Pro: Multiple authentication methods, single sign-on and permission synchronization support secure search rather than merely indexing content.
- Pro: Apache licensing allows free personal and commercial use, while JSON, JavaScript integration, plugins and API support offer routes to extend it.
- Con: Self-hosting on Java or Docker places runtime and deployment responsibility on the organization.
- Con: The open-source edition has no guaranteed support; response targets require paid, per-site professional support.
Alternatives
For a broader category comparison, see AI Enterprise Search Software.
- SWIRL AI Search is worth considering if you want a free tier and trial alongside paid evaluation and departmental options.
- PipesHub is another free, self-hosted option, with a community edition that includes Docker deployment, core indexing and search, BYO LLMs and embeddings, and a no-code agent builder.
- Dropbox Dash may fit teams seeking a paid, cross-platform product with a free trial and plans sized by user count rather than a self-hosted server.
- Onyx is an alternative if you want a freemium web product with a business plan that includes chat and search, major LLM access and custom AI agents.
- SearchBlox SearchAI is a paid alternative with a stated annual plan covering up to 10,000 documents or URLs and 100,000 searches per month.
- Viglet Turing ES is another free search option for web, Windows and Linux.
- Elastic Search AI is another freemium web option.
- Amazon Kendra is a paid alternative with a free trial and API and web platforms.
Verdict
Choose Fess if you need flexible, permission-aware enterprise search and have the capacity to run a Java- or Docker-based service. Its breadth of content sources, authentication and integration options is the strongest reason to choose it; the main reason to look elsewhere is the operational burden or the need for guaranteed support without a paid plan.
Fess plans and pricing
All plansCompared on AI enterprise search software
- Free plan
- Yesfess.codelibs.org
- Permission sync
- Yesfess.codelibs.org
- Answer citations
- Yesfess.codelibs.org
- Deployment options
- self-hostedfess.codelibs.org
- Admin controls
- Yesfess.codelibs.org
Facts
- Product
- Fess is an open-source enterprise search server for searching websites, files, and databases.fess.codelibs.org · 30 Sept 2026
- Built-in tools
- Fess includes a crawler, indexer, administration console, and search interface.fess.codelibs.org · 30 Sept 2026
- Deployment
- Fess runs on operating systems with a Java or Docker runtime environment.fess.codelibs.org · 30 Sept 2026
- Search engine
- Fess is built on OpenSearch.fess.codelibs.org · 30 Sept 2026
- Content sources
- The crawler supports web pages, file systems, Windows shared folders, and databases.fess.codelibs.org · 30 Sept 2026
- File formats
- The crawler supports formats including Microsoft Office documents and PDF, and can use external text extraction such as OCR.fess.codelibs.org · 30 Sept 2026
- Authentication
- Secure search supports BASIC, DIGEST, NTLM, and FORM authentication, plus single sign-on using Active Directory, SAML, and other methods.fess.codelibs.org · 30 Sept 2026
- Search features
- Search includes facets, drill-down, autocomplete, suggestions, cached results, and thumbnails.fess.codelibs.org · 30 Sept 2026
- Integrations
- Fess can return search results in JSON, integrate with websites using JavaScript, and extend functionality through plugins.fess.codelibs.org · 30 Sept 2026
- API
- Fess documentation covers an API, and external system integration can use access tokens.fess.codelibs.org · 30 Sept 2026
- License
- Fess is provided under the Apache License and is free for personal and commercial use.fess.codelibs.org · 30 Sept 2026
- Support
- The open-source edition is community-supported and has no guaranteed support; paid professional support is available by email.fess.codelibs.org · 30 Sept 2026
- Support response
- Professional support lists first-response targets of three business days for Silver, two for Gold, and one for Platinum.n2sm.net · 30 Sept 2026
- Latest release
- The downloads page lists Fess 15.8.0 with Java 21 and OpenSearch 3.8.0 as the latest stable release.fess.codelibs.org · 30 Sept 2026
- Maker
- CodeLibs, Inc. is located in Yokohama City, Kanagawa, Japan, and was established in November 2019.codelibs.co · 30 Sept 2026
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Sources
- fess.codelibs.org· checked 30 Sept 2026
- fess.codelibs.org/downloads.html· checked 30 Sept 2026
- fess.codelibs.org/documentation.html· checked 30 Sept 2026
- n2sm.net/en/support/fess_support.html· checked 30 Sept 2026
- codelibs.co/company/about.html· checked 30 Sept 2026





