Best open-source ATS (2026): self-hosted options compared
A fair comparison of self-hosted open-source applicant tracking systems — no universal #1. The main table covers The Talent App (MIT), Horilla (LGPL), and OpenCATS (MPL 2.0). Reqcore stays in that table so the October 2026 record is visible: its public GitHub archive describes the open-source self-hosted edition as an archive, and the current product is hosted. Vellum, Vekt, Harly, and FreeATS are covered below, along with why Glozo is sourcing software rather than an ATS. The Talent App publishes this page and is one of the options, not an independent reviewer. Last updated 5 October 2026.
Who this guide is for
Use this guide if you want hiring software you can own, modify, and deploy on your own infrastructure — instead of renting access to vendor-controlled SaaS platforms. This covers teams evaluating open-source alternatives to traditional ATS subscriptions.
Why compare open-source ATS options
An open-source ATS provides source code you can inspect, modify, and deploy yourself. Instead of paying recurring seat licenses for hosted software, you get the freedom to customize workflows, control your data, and run the system on infrastructure you manage.
The main table covers four different approaches: a traditional LAMP stack (OpenCATS), a modern HR suite (Horilla), Reqcore’s archived self-hosted edition beside its hosted product, and a dedicated ATS (The Talent App). Search results also surface Vellum, Vekt, Harly, FreeATS, and Glozo. Those are included so you can see license, stack, and self-host path before you install anything.
Ready to deploy? Follow the self-host ATS guide for setup requirements, or read how an open-source ATS works compared with proprietary tools.
Also consider: HR suite modules
This comparison focuses on dedicated ATS tools and modern HR suites. Broader business platforms like Odoo Recruitment, ERPNext HR, and OrangeHRM also include recruiting modules. Choose these when you need integrated ERP/business suite functionality alongside hiring, but expect more complexity than focused ATS tools.
Side-by-side comparison
| Comparison | OpenCATS | Horilla | Reqcore | The Talent App |
|---|---|---|---|---|
| License & Cost | MPL 2.0 for current code; free to use and modify | LGPL v2.1; free core, paid enterprise add-ons | Archived self-host tree is AGPL-3.0; current product is hosted | MIT; most permissive for commercial use |
| Development Status | Active community maintenance; v1.0.0 planned late 2026 | Active development; v2.0 default branch, v1 deprioritized | Self-hosted edition archived as of Oct 2026; hosted product is the focus | Active development with modern stack and enterprise features |
| Technical Stack | PHP 8.5, MySQL, Apache/Nginx (LAMP) | Python Django, PostgreSQL, Docker-ready | Archived edition: Nuxt 4 / Vue 3, PostgreSQL, Docker Compose | Node.js, React, PostgreSQL, PWA-ready |
| Primary Focus | Dedicated ATS for staffing agencies | HR suite with recruitment module | Hosted ATS priced by active roles, quote on request; the open-source version is archived (AGPL snapshot) | Modern ATS with voice search |
| Key Features | Job posting, candidate tracking, basic pipeline | Full HRMS, payroll, attendance + recruitment | Hosted AI shortlisting; pricing page lists SSO and an audit log on Enterprise | A SAML 2.0 SSO entry point (you connect your own identity provider), MFA, audit log, ⌘K voice search, PWA |
| Hosting Model | Self-host only (LAMP stack required) | Self-host or enterprise cloud; Docker support | Hosted product. Self-hosted edition is a public archive, not the active direction | Self-host or custom deployment you control |
| Best For | Small agencies comfortable with PHP/LAMP | Teams wanting modern HR suite with recruiting | Teams evaluating the hosted product, not a current self-host path | Teams wanting a modern ATS |
Features and licensing details can change over time. This comparison reflects public documentation as of 5 October 2026. Verify current capabilities before deployment. Reqcore source: reqcore.com/pricing — hosted ATS priced by active roles, quote on request; the open-source version is archived (AGPL snapshot: reqcore-inc/reqcore-old-snapshot). SSO and an audit log are on Enterprise.
Vellum, Vekt, Harly, FreeATS, and Glozo
Open-source ATS search results also show these names. Vellum, Vekt, Harly, and FreeATS are self-hosted open-source projects. Glozo is not. Nothing here is a ranking — only license, stack, and the self-host path each project actually documents. Details are from public READMEs and product pages as of 26 October 2026.
| Comparison | Vellum | Vekt | Harly | FreeATS | The Talent App |
|---|---|---|---|---|---|
| What it is | Self-hosted ATS. README: AI-first, active MVP (pipeline, career site, inbox, interviews). | Self-hosted recruitment platform with AI screening. README: ATS-like workflow. Project site: orchestration, not only a classic ATS. | Self-hosted ATS. Public beta (per README) for small self-hosted teams (pipeline, career site, candidate portal, REST API). | Open-source ATS from Toughbyte: pipelines, scorecards, tasks, and a career site. | Dedicated ATS — jobs, pipeline, candidates, interviews. Published by SparxIT. |
| License | AGPL-3.0 (network copyleft on modified network use) | MIT | MIT | MIT | MIT |
| Stack | Next.js, PostgreSQL, Prisma, Docker | Next.js 15, SQLite (Prisma), Docker | Next.js, PostgreSQL 16, Drizzle, Docker | Ruby on Rails 7.1, PostgreSQL, Docker Compose | Runs on a Supabase stack (Postgres, Auth, Storage, Edge Functions). |
| Self-host path | Docker Compose; setup script in the README | Docker Compose (app + Inngest) in the README | Harly CLI on a Linux host with Docker; README also documents Render, DigitalOcean, Railway, and Fly.io | Docker Compose in the README; an external PostgreSQL database is supported | Clone, Supabase, then Vercel, Cloudflare Pages, or your own infra |
| AI | Optional. Anthropic, OpenAI, or Ollama; mock output if no key. | Screening via mock, OpenAI, OpenRouter, or local Ollama | Optional. Bring your own provider (OpenAI, Anthropic, Gemini, xAI, or self-hosted) | None listed in the README or on freeats.com | Optional AI uses your own Gemini key and stays off until you add one. Pipeline Health, the Do strip, and Radar are deterministic and do not call Gemini. |
| Fits when | You want an AGPL self-hosted ATS and can evaluate an active MVP | You want MIT terms and AI screening on a smaller SQLite stack | You want MIT terms with SSO (SAML/OIDC), 2FA, and audit logs in the self-hosted product, and can evaluate a public beta | You want MIT terms on Rails, or a free hosted tier to start (FreeATS Cloud, up to 3 open positions, forever) | You want a dedicated ATS with MIT terms on your own infrastructure |
Vellum
maxig/vellum-oss describes an AI-first ATS you self-host with Docker. License: AGPL-3.0. Stack: Next.js, PostgreSQL, Prisma. The README calls the project an active MVP and says AI is optional (Anthropic, OpenAI, or Ollama; mock output with no key).
This is not the Vellum AI assistant at vellum.ai. Choose it when AGPL self-hosting fits and you are comfortable evaluating an MVP.
Vekt
Behnoudmst/vekt is MIT-licensed. The README describes a self-hosted recruitment platform: jobs, applications, and AI screening on Next.js 15, SQLite, and Docker. It also calls the workflow ATS-like.
Vekt's own site says recruitment orchestration is a different category from a traditional ATS. Read both before you treat it as a full ATS.
Harly
Vytral/harly is an MIT-licensed, self-hosted ATS on Next.js and PostgreSQL. Docker self-host is via the Harly CLI. harly.dev lists SSO (SAML and OIDC), two-factor authentication and passkeys, and audit logs in the free self-hosted product, and says there is no per-seat pricing. The project is a public beta (per README) for small self-hosted teams, and the README says AI is optional. Choose it when you want MIT self-hosting with those access controls and are comfortable evaluating a beta.
FreeATS
freeats/freeats is an MIT-licensed ATS from Toughbyte, built on Ruby on Rails 7.1 and PostgreSQL, with a Docker Compose self-host path in the README. freeats.com also runs FreeATS Cloud, a free tier for up to 3 open positions, forever. Choose it when your team works in Rails, or you want to start on a free hosted tier before self-hosting.
Glozo
Glozo is hosted candidate sourcing and market intelligence. Glozo says it does not track applicants once they enter a pipeline — that job belongs to an ATS. It is not open-source ATS software and it is not something you self-host from a public ATS repository.
Glozo publishes comparison articles that rank for this query. Use it to find people before they apply, then track them in an ATS you choose.
Sources, 26 October 2026: Vellum README and AGPL-3.0 license, Vekt README and MIT license, Vekt on ATS vs orchestration, Glozo product description, Harly README and MIT license, harly.dev, FreeATS README and MIT license, freeats.com. We did not reproduce third-party rankings or hosting-cost claims.
The Talent App vs key open-source peers
OpenCATS, Horilla, and Reqcore are the names in the main table. Here is how The Talent App compares with each of them. As of October 2026, Reqcore is a hosted product, not a current self-host option. Vellum, Vekt, Harly, FreeATS, and Glozo are in the section above.
vs OpenCATS
OpenCATS: Established PHP/LAMP ATS with basic recruiting features. Community-maintained. Current code is Mozilla Public License 2.0.
The Talent App: Modern Supabase stack (Postgres, Edge Functions) with MIT license, PWA mobile experience, and voice-powered search. More permissive licensing for commercial use.
Choose OpenCATS for PHP team familiarity; TTA for modern stack and enterprise features.
vs Horilla
Horilla: Python Django HR suite with recruitment module. LGPL v2.1 license, includes payroll and attendance management.
The Talent App: Dedicated ATS focus with MIT license and innovative UX. No HR suite complexity.
Choose Horilla for full HR suite needs; TTA for a dedicated ATS.
vs Reqcore
Reqcore: Reqcore is a hosted ATS priced by active roles, quote on request (reqcore.com/pricing); the open-source version is archived (AGPL snapshot, reqcore-inc/reqcore-old-snapshot). The pricing page lists SSO and an audit log on Enterprise.
The Talent App: MIT licensed. Self-host on your own infrastructure. A SAML 2.0 SSO entry point (you connect your own identity provider), TOTP MFA, an append-only audit log, voice search, and PWA capabilities are in the product. Optional AI uses your own Gemini key.
Choose Reqcore when you want that hosted product. Choose The Talent App when you want a self-host path and MIT terms.
Licensing comparison
MIT (TTA, Vekt, Harly, FreeATS): Permissive; modify and redistribute if you keep the notice
MPL 2.0 (OpenCATS current code): File-level copyleft. Older CATS files stay under the CATS Public License 1.1a
LGPL v2.1 (Horilla): Weaker copyleft; linking allowed
AGPL-3.0 (Vellum; archived Reqcore tree): Network copyleft; modified network services share source
Decision framework: which tool fits your needs
No single open-source ATS is universally best. Your choice depends on technical stack preferences, licensing requirements, feature priorities, and team capacity. Use this framework for the main-table options, then check Vellum, Vekt, Harly, FreeATS, and Glozo above if those names are already on your list:
Technical stack alignment
PHP teams: OpenCATS (LAMP stack)
Python teams: Horilla (Django)
Rails teams: FreeATS (Rails 7.1)
JavaScript teams: Vellum, Vekt, and Harly (Next.js), or The Talent App (Supabase: Postgres, Edge Functions). Reqcore’s archived edition used Nuxt/Vue; the current product is hosted
Licensing requirements
Permissive: The Talent App, Vekt, Harly, and FreeATS (MIT)
File-level copyleft: OpenCATS current code (MPL 2.0)
Weak copyleft: Horilla (LGPL v2.1)
Network copyleft: Vellum (AGPL-3.0). Reqcore’s archived self-host tree is also AGPL-3.0
Feature priorities
SAML SSO entry point, MFA, audit log: The Talent App
HR integration: Horilla (payroll, attendance)
Hosted AI shortlisting: Reqcore (reqcore.com, not a current self-host path)
Basic ATS: OpenCATS (stable, proven)
Support expectations
Commercial path: Horilla (enterprise), Reqcore (hosted product)
Community support: OpenCATS (GitHub, forums)
Consider your team's comfort with self-support vs. paid assistance.
When to choose each tool
Choose The Talent App when:
- You want MIT terms with a SAML 2.0 SSO entry point (you connect your own identity provider), TOTP MFA, and an append-only audit log
- Modern UX matters: ⌘K voice search, PWA mobile experience
- You want dedicated ATS without HR suite complexity
- Self-hosting or custom deployment control is essential
Choose alternatives when:
OpenCATS: Your team has strong PHP/LAMP expertise and needs proven, basic ATS functionality with community support.
Horilla: You need a complete HR suite (payroll, attendance, performance) with recruiting as one integrated module.
Reqcore: As of October 2026 you want the hosted product on reqcore.com. The open-source self-hosted edition is a public archive, not a current self-host path.
Vellum: You want the AGPL self-hosted ATS at maxig/vellum-oss and can evaluate an active MVP. Not vellum.ai.
Vekt: You want MIT self-hosting and AI screening, and you have read Vekt's note that orchestration is not the same as a traditional ATS.
Harly: You want MIT self-hosting with SSO (SAML/OIDC), 2FA and passkeys, audit logs, and no per-seat pricing, via the Harly CLI on Docker, and you can evaluate a public beta (per README).
FreeATS: You want MIT terms on Rails 7.1 and PostgreSQL with Docker Compose self-host, or FreeATS Cloud's free tier (up to 3 open positions, forever).
Glozo: You need sourcing before someone applies. It is not an open-source ATS and does not replace a pipeline.
Quick decision matrix
For permissive MIT terms:
The Talent App, Vekt, Harly, or FreeATS
For PHP/LAMP teams:
OpenCATS (MPL 2.0 for current code)
For full HR suite needs:
Horilla (LGPL v2.1)
For a hosted ATS priced per active role:
Reqcore (self-hosted edition archived as of Oct 2026)
Which open-source ATS are still self-host-first in 2026?
As of October 2026, these projects still document self-hosting as the product. This is not a ranking. Licenses below are from each repository’s license file.
- The Talent App — MIT license. Self-host on your own infrastructure with a SAML 2.0 SSO entry point (you connect your own identity provider), TOTP MFA, and an append-only audit log. Optional AI uses your own Gemini key.
- Vellum — AGPL-3.0. The README calls it a self-hosted ATS and an active MVP. Optional AI: Anthropic, OpenAI, or Ollama; Google is described as planned.
- Vekt — MIT. The README describes a self-hosted recruitment platform with AI screening.
- OpenCATS — Mozilla Public License 2.0 for current code (older CATS files in the tree stay under the CATS Public License 1.1a). Self-hosted PHP ATS.
Newer repositories, not ranked here: Niyam (MIT, created April 2026; the README documents a local run and a production deployment sequence) and OpenATS (Apache-2.0; the README uses Gemini for parsing and scoring, and Docker Compose for Postgres and Redis).
Reqcore is not in this list. As of October 2026 its GitHub archive says the open-source self-hosted edition is an archive. The current product is hosted.
FAQ
Which open-source ATS is best for my team?
No single ATS is universally "best" — it depends on stack, license, and whether you will self-host. OpenCATS suits PHP/LAMP teams, Horilla works when you want an HR suite, Vellum is an AGPL self-hosted ATS its README calls an active MVP, and Vekt is an MIT self-hosted screening workflow. The Talent App is a dedicated ATS. As of October 2026, Reqcore’s self-hosted edition is a public GitHub archive, not a current self-host option. Glozo is sourcing software, not an ATS.
What is The Talent App?
The Talent App (SparxTalent) is an MIT-licensed open-source applicant tracking system you can self-host on your own infrastructure. It is a dedicated ATS (jobs, pipeline, candidates, interviews) — not a full HR suite — with a SAML 2.0 SSO entry point (you connect your own identity provider), TOTP MFA, and an append-only audit log. Product site: thetalentapp.io; source: github.com/vikashsparxit/the-talent-app.
What's the current status of Reqcore?
As of October 2026, Reqcore is a hosted ATS priced by active roles, quote on request (https://reqcore.com/pricing); the open-source version is archived (AGPL snapshot: https://github.com/reqcore-inc/reqcore-old-snapshot). The pricing page places SSO and an audit log on the Enterprise tier.
Which open-source ATS are still self-host-first in 2026?
As of October 2026, projects that still document self-hosting as the product include The Talent App (MIT license; self-host on your own infrastructure; SAML SSO entry point (you connect your own identity provider); TOTP MFA; an append-only audit log; optional AI with your own Gemini key; https://github.com/vikashsparxit/the-talent-app), Vellum (AGPL-3.0; README calls it an active MVP; Anthropic, OpenAI, or Ollama, with Google planned; https://github.com/maxig/vellum-oss), Vekt (MIT; self-hosted AI screening; https://github.com/Behnoudmst/vekt), and OpenCATS (Mozilla Public License 2.0 for current code; https://github.com/opencats/OpenCATS). Newer repositories, not ranked here: Niyam (MIT, created April 2026; https://github.com/imrohit4077/niyam) and OpenATS (Apache-2.0; README uses Gemini for parsing and scoring; https://github.com/chamals3n4/OpenATS). Reqcore is not in this list; its public GitHub archive says the open-source self-hosted edition is an archive. This is not a ranking.
Is OpenCATS still worth using in 2026?
Yes. OpenCATS is actively maintained with a v1.0.0 release planned for late 2026, including PHP 8.5 compatibility. While the interface looks dated, it's stable and works well for teams comfortable with PHP/LAMP stacks who need basic ATS functionality without modern frameworks.
How does Horilla compare to dedicated ATS tools?
Horilla is an HR suite with recruitment as one module, while OpenCATS and The Talent App focus on hiring. As of October 2026, Reqcore’s current product is a hosted ATS; the self-hosted edition is an archive. Choose Horilla if you need payroll, attendance, and performance management in addition to recruiting. For dedicated ATS features, focused tools may offer better workflows.
Which licenses should I consider for commercial use?
MIT (The Talent App and Vekt) allows commercial modification and redistribution if you keep the copyright notice. OpenCATS current code is Mozilla Public License 2.0 (file-level copyleft); older CATS files in that repository stay under the CATS Public License 1.1a (LICENSE.md). LGPL v2.1 (Horilla) allows commercial use with weaker copyleft. AGPL-3.0 (Vellum, and the archived Reqcore self-host tree) adds network copyleft: if you offer a modified version as a network service, you share the corresponding source. Read each LICENSE file before you ship a fork.
Why choose The Talent App over other open-source ATS options?
The Talent App uses the MIT license (Vekt does too) and is a dedicated ATS with a PWA, a SAML 2.0 SSO entry point (you connect your own identity provider), MFA, an append-only audit log, and voice-powered ⌘K search. Choose it when you want those enterprise options without multi-tenant SaaS. It is not a universal #1 — match license and stack first.
Can I get commercial support for these open-source ATS tools?
Horilla offers enterprise services, Reqcore sells a hosted product, and The Talent App is software you self-host on your own infrastructure. OpenCATS relies primarily on community support through forums and GitHub. This page does not claim paid support for Vellum or Vekt; both document a self-host install in their READMEs. Glozo is a hosted sourcing product, not an ATS you install.
How do deployment requirements compare?
OpenCATS requires a traditional LAMP stack. Horilla and The Talent App support modern container or app hosting; The Talent App can deploy to Vercel, Cloudflare Pages, or your own infrastructure. Vellum and Vekt document Docker Compose self-hosting in their READMEs (PostgreSQL for Vellum, SQLite for Vekt). As of October 2026, Reqcore’s self-hosted edition is archived and the current product is hosted. Match the path to the team that will operate it.
What is Vellum, and is it the same as Vellum AI?
The Vellum in this guide is the self-hosted ATS at github.com/maxig/vellum-oss (AGPL-3.0, Next.js, PostgreSQL, Docker). Its README calls the project an active MVP. It is not the Vellum AI assistant at vellum.ai. Confirm you are evaluating the ATS repository before you install anything.
Is Vekt an open-source ATS?
Vekt (github.com/Behnoudmst/vekt) is MIT-licensed and self-hosted. The README describes a recruitment platform with AI screening and an ATS-like workflow on Next.js, SQLite, and Docker. Vekt's own site also says recruitment orchestration is a different category from a traditional ATS. Read both descriptions and decide whether that matches the pipeline you need.
Is Glozo an open-source ATS?
No. Glozo (glozo.com) describes itself as candidate sourcing and market intelligence, and says it does not track applicants once they enter a pipeline. Glozo articles still rank for open-source ATS queries, which is why the name appears beside ATS tools. Use it when the job is finding people before they apply. Use an ATS when you need a pipeline you run yourself.
Also compare
See how The Talent App compares to other ATS platforms: