How much does it actually cost to run an open-source ATS?

A basic VPS (DigitalOcean, Hetzner, Linode) for a single-recruiter install runs $5 to $15 per month. Add setup time: 2 to 4 hours for OpenCATS or OrangeHRM, longer for Odoo or ERPNext. And occasional maintenance for updates. Total first-year cost for a technically capable recruiter is roughly $120 to $180 in hosting, plus your time.

Which open-source ATS options should I avoid in 2026?

Two, as of September 2026. CandidATS has had no code pushed since November 2015 and its own README calls it alpha software not suitable for production, yet it still appears on 2026 comparison lists. Reqcore is the subtler case: the AGPL repository is still public, but the company archived that positioning and now sells hosted software from $79 a month, with self-hosting absent from its site, so the free self-hosted tool other guides describe is not what you would be getting. The check that catches both takes a minute. Open the project's repository and read the date of the last commit and of the most recent release before you put candidate data behind it.

Is OpenCATS still actively maintained in 2026?

Yes, and more actively than its interface suggests. Commits were landing in September 2026 and version 0.10.0 shipped in June 2026. The maintenance to plan for is patching rather than development. Five security advisories were published against OpenCATS in 2026, including a critical remote-code-execution flaw in the import feature, and all five are fixed only in 0.10.0. The release before that was in April 2024, so fixes arrive when they are needed rather than on a schedule. If you self-host OpenCATS, you are the person responsible for noticing a release like that and applying it.

Is "open-source recruiting software" the same as an open-source ATS?

Mostly, the terms get used interchangeably. An ATS is the specific category that tracks applicants through a hiring pipeline. "Recruiting software" is the broader bucket that can also include sourcing tools, CRM-style candidate nurturing, and HR suites with a recruitment module, like Horilla, Odoo, or ERPNext. If you only need to track candidates, you want an ATS. If you need to find or nurture them, look wider.

What's the difference between an open-source ATS and a recruiting CRM?

An ATS tracks candidates who are already in a live hiring process, from application to offer. A recruiting CRM works the proactive side: finding and nurturing potential candidates over time, before a role opens, across a pool that includes passive candidates, past applicants, and referrals. Most open-source tools are ATS-first. A few, like OpenCATS and Horilla, add light CRM features, but no open-source option matches a dedicated commercial CRM on relationship management.

Should I pick a standalone ATS or an HR suite with a recruitment module?

Ask how many other systems you are willing to run. A standalone ATS like OpenCATS does one job, installs in an afternoon, and leaves payroll and employee records to whatever you already use. An HR suite with a recruitment module, which is what Horilla, Odoo, ERPNext and OrangeHRM are, only pays off when you want the other modules too, because you stand up the whole platform before you reach the hiring part. So if recruiting is the only thing you need software for, the standalone ATS wins. If you are also about to buy something for leave, payroll or employee records, the suite is the cheaper path.

Can I use Odoo Recruitment without the rest of the Odoo suite?

Technically yes, but the setup overhead is substantial, and a standalone Recruitment module does not justify standing up a full Odoo instance. If you are not using other Odoo modules, OpenCATS, CandidATS, or Reqcore gives you the same tracking capability with far less setup time.

Does self-hosting mean my candidate data is more private?

Yes, if you maintain the server properly. You control the database entirely and no third-party vendor holds your candidate records. The trade-off is that security is your responsibility. You need to keep the software current, secure the server, and manage backups. A managed SaaS ATS handles that maintenance for you.

Guide

Open-source ATS in 2026: what each tool actually costs to run

Eight open-source applicant tracking systems, re-checked in September 2026. What each really costs to host, the two that no longer hold up, and when paying for an ATS is cheaper.

Alex Vavilov

Updated Sep 10, 2026

Originally Sep 8, 2025

You're tracking 20 open roles, a client retainer, and three active pipelines. The ATS platforms built for that work charge by the seat, and the bill arrives whether you make a placement that month or not. On a small desk the software can cost more than a placement brings in. That's the real reason recruiters and small hiring teams look at open-source ATS options.

But "open-source" covers a lot of ground in 2026, and two of the tools you will still see recommended no longer hold up. One has had no code committed to it since 2015. The other had its open-source build archived by the company that made it, which now sells hosted software instead. This guide covers what is actually available, what each one costs to operate, and which setup fits which situation.

One thing to get straight before you start: an ATS solves a tracking problem, not a sourcing one. If the line between the two is fuzzy, this breakdown of sourcing versus recruiting is worth two minutes.

Every price, licence and project status below was re-checked on 10 September 2026 against the vendor's own pricing page or the project's own repository.

What "open-source ATS" actually means for your budget

Open-source means the source code is public and free to use. It does not mean zero cost.

You need a server (a basic VPS runs $5 to $20 per month), time to set it up (plan on a half-day minimum for the simpler tools), and ongoing attention when updates or security patches come out. For a solo recruiter with no technical background, that time cost often outweighs what you would pay for a basic paid ATS.

For recruiters with a developer on the team, or anyone comfortable with command-line setup, the math works the other way. A small cloud server and an afternoon is all it takes to run a stable system indefinitely. Worth knowing that the round $10 server most guides quote is not a real product: DigitalOcean steps straight from $6 to $12 a month, and Hetzner's cheapest EU instance is EUR 5.49 before VAT. What a self-hosted ATS will not do is help you find candidates. For that side of the stack, see the free resume search tools guide.

Eight open-source ATS tools at a glance

Tool	Type	Setup effort	Monthly hosting cost	Best for	Key limitation
OpenCATS	Traditional ATS	2–4 hours	$5–$15 (self-hosted)	Basic candidate pipeline tracking	Dated UI, no integrations, no mobile, and you apply the security releases
CandidATS	Abandoned fork of OpenCATS	Do not install	n/a	Nothing in 2026	No code pushed since November 2015; alpha by its own README
Reqcore	Hosted SaaS since 2026	Vendor-hosted	Free for one active role, then from $79	Teams who want it hosted and will take a sales call	The open-source self-hosted build is archived by the vendor
OpenClaw	AI sourcing agent	Under 1 hour to install since 2.0; most of a day for a first workflow	$0 (runs locally)	Automated sourcing and outreach	No candidate database of its own, and its security controls ship switched off
Horilla	HRMS + recruitment	3–5 hours	$0 self-hosted, or $7 per user cloud	Teams wanting recruiting inside a free HR suite	Recruitment is one module of many
Odoo Recruitment	ATS module (ERP)	Full day+	$0 self-hosted; paid plans from $24.90 per user, and Odoo.sh needs the $49 plan	Teams already on the Odoo ecosystem	Overkill as a standalone ATS
ERPNext HR	ATS module (ERP)	Full day+	$0 self-hosted, or Frappe Cloud from $5	ERPNext users who need recruiting built in	ERP first, ATS second
OrangeHRM	HR suite + ATS	2–3 hours	$0 self-hosted; paid cloud priced on request	Small HR teams with light recruiting needs	Weak for agency recruiting, and paid pricing is quote-only with a 25-employee minimum

OpenCATS

Best for: Solo recruiters who need a stable pipeline tracker and can live with a dated interface.

OpenCATS has been around since the mid-2000s and is still on GitHub, with commits landing in the same week this was written. It handles the core tracking workflow: import resumes, create job orders, move candidates through pipeline stages, log call notes, and generate basic reports. The interface looks like it was designed in 2008, because most of it was. It is stable, well-documented, and free. Our full OpenCATS review digs into setup, the real cost, and whether building your own is ever worth it. It also bills itself as a recruitment CRM, though in practice the relationship-nurturing side is thin compared to a real CRM. If candidate nurturing is what you are after, the open-source recruiting CRM options are worth a separate look.

Setup: OpenCATS runs on PHP 8 with MariaDB. Its own documentation is explicit that MySQL is not the tested database target, so use MariaDB even though most guides online still say otherwise. On a small cloud server most recruiters are running in a few hours using the community guides. The repository carries a docker directory, but the documentation treats Docker as a testing tool rather than a supported install path, so plan for a manual install.

What it does not do: No mobile app. No job board integrations. No candidate-facing email sequences. You import candidates manually or via resume parsing, and all pipeline activity happens inside the tool. Every outreach step is something you handle separately. Patching is the other thing to plan for. Five security advisories were published against OpenCATS in 2026, one of them a critical remote-code-execution flaw in the import feature, and all five are fixed only in version 0.10.0. That release came out in June 2026, twenty-six months after the one before it. Self-hosting means you are the person who has to notice a release like that and apply it.

If your workflow is "I find candidates, I need somewhere to put them," OpenCATS does that without fuss. If you need active sourcing from inside your tool, it will not help.

CandidATS

Verdict: do not use it. It stays on this list because other 2026 comparison guides still recommend it.

CandidATS began as a fork of OpenCATS 0.9.1, aiming for cleaner code. Then it stopped. No code has been pushed to the repository since 5 November 2015, it has never cut a release, and its own README describes the software as alpha and not suitable for production use. Nine people have starred it.

Why it matters: that is a decade of drift from a parent project that has since shipped through 0.10.0 and patched a critical remote-code-execution flaw. Anything CandidATS inherited from OpenCATS 0.9.1 predates every one of those fixes, and there is nobody to apply the next one.

The honest read: if you want the OpenCATS feature set, run OpenCATS. Nothing about this fork is worth putting candidate records behind code that has not been touched in ten years.

Reqcore

Verdict: the open-source version is no longer the product. Reqcore sells hosted software now.

Reqcore used to be the most direct answer to the most common complaint about OpenCATS, which is the interface: a current stack, a single Docker Compose command, no per-seat pricing. The repository is still public and still AGPL. The company has moved on from it. The page that told that story now carries the notice "Archived design, this page does not reflect Reqcore's current product or positioning", and the old code sits in a second repository the company itself labels an archive of the self-hosted version.

What it costs now: the free plan covers one active role. Paid plans start at $79 a month, and all three published tiers are listed as "Price on the call". Self-hosting is not mentioned anywhere on the site.

How to read it: there are two Reqcores in 2026 and neither is the one the listicles describe. You can run the archived code yourself, with no vendor behind it and no releases to follow. Or you can buy the hosted product, which is neither free nor self-hosted and is priced by conversation. Decide which of those you are actually evaluating before you spend an afternoon on it.

One more name you will run into. RabbitHR comes up often on this topic, including inside Google's own AI summary, described as a free MIT-licensed ATS you can host yourself. We could not verify that. The repository its own open-source page points to did not contain the product when we looked on 10 September 2026, a GitHub search for the project returned nothing, and there is no published image on Docker Hub. That may be a documentation problem rather than anything else, and it may have changed by the time you read this. Run the same check yourself before you plan around it: open the repository, read the date of the last commit, and see whether the install instructions match what is actually there.

OpenClaw

Best for: Recruiters who want to automate sourcing and outreach, not just track candidates after they have been found.

OpenClaw is a different category entirely. It is an open-source AI agent (389,000+ GitHub stars as of September 2026, with its 2.0 release out at the end of August) built to run multi-step autonomous workflows. For recruiters, that means finding candidates who match a set of criteria across GitHub, LinkedIn, and other sources, drafting outreach based on their actual project history, and running the follow-up sequence without you touching each step.

It runs locally or on a server and keeps all candidate data on your own machine. You configure it with modular "skills" (pre-built or custom) for each part of the workflow. The technical bar is higher than OpenCATS. You need to understand how to set up and connect tools, configure models (it supports GPT-5, Claude, and others), and define your sourcing parameters.

Worth the setup time if your primary challenge is sourcing volume. Glozo's detailed breakdown of OpenClaw for recruiting workflows covers the setup and what it can and cannot automate: OpenClaw: a guide to talent sourcing. If you are weighing OpenClaw against the wave of "AI recruiter" products, how to tell a real AI sourcing agent from a chatbot with a wrapper is the screen to run first.

Horilla

Best for: Small teams that want recruiting inside a free, self-hosted HR system.

Horilla is an open-source HRMS built on Django and PostgreSQL. The recruitment module covers job postings, applicant tracking, customizable pipeline stages with drag-and-drop, and interview scheduling, and it sits alongside payroll, leave, and a separate CRM module. Self-hosted, it costs nothing regardless of headcount.

Setup: Self-hosted on your own server, roughly a few hours for someone comfortable with Django deployments.

Limitation: Recruiting is one module among many. If your only need is candidate tracking, a focused ATS gets you there with less to maintain. The appeal is running HR and hiring in one free system rather than recruiting on its own.

Odoo Recruitment

Best for: Teams already running Odoo who want recruiting integrated with HR, payroll, and operations.

Odoo is a full business management suite with dozens of modules. The Recruitment module is capable: careers pages, application management, screening questions, interview scheduling, and offer tracking. It integrates directly with payroll, employee records, and project management if you are using those Odoo modules.

Setup: The Community edition is free and self-hosted. Standing up the full Odoo instance before you get to the Recruitment module takes a full day minimum, and a developer for any customization. If you want Odoo to host it, the numbers are steeper than they look. The cheapest paid plan is $24.90 per user per month billed yearly, Odoo.sh hosting is only offered on the Custom plan at $49 per user per month, and Odoo's own pricing page states that the Odoo.sh hosting cost is not included in that figure.

Limitation: Overkill for a solo recruiter or agency that only needs an ATS. The value shows when you are running four or five Odoo modules in parallel. If you are not already in the Odoo ecosystem, the setup investment is not worth it for recruiting alone.

ERPNext HR module

Best for: Organizations running ERPNext who want recruiting inside the same system.

ERPNext is an open-source ERP similar to Odoo. Its HR module includes job postings, applicant tracking, interview management, and offer letters. Like Odoo, the recruiting features make sense when the rest of your business already runs in ERPNext.

Setup: Full ERPNext instance required. Self-hosted is free but technically demanding. Frappe Cloud, the managed option, starts at $5 a month for a small site and runs to $50 at the top of its published site tiers, with dedicated servers from $40. Prices are published in both dollars and rupees.

Limitation: An ERP first, ATS second. Solo recruiters and agencies have no practical reason to use it as a standalone recruiting tool.

OrangeHRM

Best for: Small HR teams with basic recruiting needs alongside HR administration.

OrangeHRM's Community edition is free and self-hosted. It covers leave management, employee records, and a basic recruitment module: job postings, applicant tracking, and interview scheduling. The UI is cleaner than OpenCATS and the setup is more straightforward.

Setup: Available as a self-hosted install or Docker container. OrangeHRM publishes no price for the paid cloud version. Its pricing page quotes per employee per month, sets a 25-employee minimum on the Advanced plan, and routes you to a contact form, so budget for a sales conversation rather than a number.

Limitation: The recruiting module handles internal HR workflows better than external agency recruiting. If you are managing candidates across multiple client job orders, it starts to feel constrained quickly. For internal hiring teams it works. For agency recruiters, OpenCATS or OpenClaw is a better fit.

How to choose

Two questions narrow this down.

Do you have someone who can handle technical setup? If not, self-hosted open-source tools are not the right answer. Zoho Recruit runs a genuinely free tier at one active job per recruiter licence, and Manatal starts at $15 per user per month on annual billing, $19 on monthly. Either one has you posting the same day with no server to own. The savings from free software disappear fast when setup takes days.

What is your actual bottleneck, tracking candidates or finding them? The traditional tools here (OpenCATS, OrangeHRM, and the recruitment modules inside Horilla, Odoo and ERPNext) solve the tracking problem. They store candidates you have already found. If you spend most of your time on sourcing, running boolean searches, and sending outreach, a passive database does not address that at all. OpenClaw is the only option here that targets the sourcing side directly. If the admin load is what is killing you, recruiting workflow automation walks through which steps you can actually hand off.

For market data before you reach out, salary ranges for a specific role in a specific city, or which companies are actively hiring for a skill set, Glozo's Market Intelligence pulls live data without requiring a login. Useful when you are doing compensation research before a client call, or need to know the talent supply before committing to a search.

If your primary problem is finding qualified candidates in the first place, Glozo handles sourcing, compensation estimates, and outreach in one place, with no server to maintain.

Before you build, check who's actually available

Run a free search on Glozo for your next open role. See candidate supply, salary ranges, and open-to-offers signals before you commit to the search. No credit card, no ATS setup required.

Frequently asked questions

How much does it actually cost to run an open-source ATS?: A basic VPS (DigitalOcean, Hetzner, Linode) for a single-recruiter install runs $5 to $15 per month. Add setup time: 2 to 4 hours for OpenCATS or OrangeHRM, longer for Odoo or ERPNext. And occasional maintenance for updates. Total first-year cost for a technically capable recruiter is roughly $120 to $180 in hosting, plus your time.
Which open-source ATS options should I avoid in 2026?: Two, as of September 2026. CandidATS has had no code pushed since November 2015 and its own README calls it alpha software not suitable for production, yet it still appears on 2026 comparison lists. Reqcore is the subtler case: the AGPL repository is still public, but the company archived that positioning and now sells hosted software from $79 a month, with self-hosting absent from its site, so the free self-hosted tool other guides describe is not what you would be getting. The check that catches both takes a minute. Open the project's repository and read the date of the last commit and of the most recent release before you put candidate data behind it.
Is OpenCATS still actively maintained in 2026?: Yes, and more actively than its interface suggests. Commits were landing in September 2026 and version 0.10.0 shipped in June 2026. The maintenance to plan for is patching rather than development. Five security advisories were published against OpenCATS in 2026, including a critical remote-code-execution flaw in the import feature, and all five are fixed only in 0.10.0. The release before that was in April 2024, so fixes arrive when they are needed rather than on a schedule. If you self-host OpenCATS, you are the person responsible for noticing a release like that and applying it.
Is "open-source recruiting software" the same as an open-source ATS?: Mostly, the terms get used interchangeably. An ATS is the specific category that tracks applicants through a hiring pipeline. "Recruiting software" is the broader bucket that can also include sourcing tools, CRM-style candidate nurturing, and HR suites with a recruitment module, like Horilla, Odoo, or ERPNext. If you only need to track candidates, you want an ATS. If you need to find or nurture them, look wider.
What's the difference between an open-source ATS and a recruiting CRM?: An ATS tracks candidates who are already in a live hiring process, from application to offer. A recruiting CRM works the proactive side: finding and nurturing potential candidates over time, before a role opens, across a pool that includes passive candidates, past applicants, and referrals. Most open-source tools are ATS-first. A few, like OpenCATS and Horilla, add light CRM features, but no open-source option matches a dedicated commercial CRM on relationship management.
Should I pick a standalone ATS or an HR suite with a recruitment module?: Ask how many other systems you are willing to run. A standalone ATS like OpenCATS does one job, installs in an afternoon, and leaves payroll and employee records to whatever you already use. An HR suite with a recruitment module, which is what Horilla, Odoo, ERPNext and OrangeHRM are, only pays off when you want the other modules too, because you stand up the whole platform before you reach the hiring part. So if recruiting is the only thing you need software for, the standalone ATS wins. If you are also about to buy something for leave, payroll or employee records, the suite is the cheaper path.
Can I use Odoo Recruitment without the rest of the Odoo suite?: Technically yes, but the setup overhead is substantial, and a standalone Recruitment module does not justify standing up a full Odoo instance. If you are not using other Odoo modules, OpenCATS, CandidATS, or Reqcore gives you the same tracking capability with far less setup time.
Does self-hosting mean my candidate data is more private?: Yes, if you maintain the server properly. You control the database entirely and no third-party vendor holds your candidate records. The trade-off is that security is your responsibility. You need to keep the software current, secure the server, and manage backups. A managed SaaS ATS handles that maintenance for you.