# Prowlarr: one indexer manager for Sonarr, Radarr and the rest of the *arr stack

> Prowlarr centralises Torrent Tracker and Usenet Indexer configuration, then syncs it to Lidarr, Mylar3, Radarr, Readarr and Sonarr so you configure indexers once. Here is how the sync works, what it does not do, and where it stops being the right tool.

**Prowlarr/Prowlarr** — Prowlarr is an indexer manager/proxy built on the popular *arr .net/reactjs base stack to integrate with your various PVR apps, supporting management of both Torrent Trackers and Usenet Indexers.

- Repository: https://github.com/Prowlarr/Prowlarr
- Website: https://prowlarr.com
- Stars: 7,293 · Forks: 398
- Language: C#
- License: GPL-3.0
- Published: 2026-09-22 · Updated: 2026-09-22 · Language: en
- Canonical page: https://hysenlabs.com/projects/prowlarr-prowlarr

## The problem Prowlarr solves: indexer configuration multiplied by the number of apps

A typical *arr setup has more than one application. Sonarr handles series, Radarr handles films, Lidarr handles music, Readarr handles books. Each of them needs to know which trackers and Usenet indexers to query. Without a shared layer, that means entering the same API keys, cookies and credentials into every app, and repeating the work every time a tracker changes its domain or your credentials rotate.

Prowlarr is the shared layer. The README describes it as an "indexer manager/proxy" that integrates with Lidarr, Mylar3, Radarr, Readarr and Sonarr, with "no per app Indexer setup required". You configure indexers in Prowlarr and it pushes that configuration to the other applications. It is aimed at people running a multi-app media stack, not at someone who wants a single search box.

The proxy part matters too. Prowlarr can route requests per indexer through SOCKS4, SOCKS5, HTTP or Flaresolverr, which is how you deal with a tracker that sits behind Cloudflare or that you only want to reach through a particular network path. That setting lives in Prowlarr rather than in each consuming app.

## How indexer sync actually flows between Prowlarr and your PVR apps

The mechanism is configuration propagation, not query interception. Prowlarr holds the indexer definitions and the credentials, and it writes that configuration into the connected applications through their APIs. The README lists "Indexer Sync to Lidarr/Mylar3/Radarr/Readarr/Sonarr, so no manual configuration of the other applications are required" as a major feature. Practically, that means when you add a tracker in Prowlarr, the corresponding indexer entry appears in Sonarr and Radarr without you typing it again.

Indexer definitions come from two sources. There are native definitions, and the README gives numbers: Usenet support for 24 indexers natively, and Torrent support for over 500 trackers. Beyond those, any Newznab compatible indexer works through "Generic Newznab", and any Torznab compatible tracker through "Generic Torznab". That is the escape hatch when your indexer is not in the built-in list.

For indexers that need custom parsing, Prowlarr supports custom YML definitions via Cardigann, including JSON and XML parsing. The repository has a schemas/ directory at the top level and the README links a wiki article on the Cardigann YML definition format, so the definition file is a first-class extension point rather than an afterthought.

The frontend is a React application built with webpack (the package.json has build, start and watch scripts pointing at frontend/build/webpack.config.js), and it talks to the C# backend. The package.json lists @microsoft/signalr, which is the library used for real-time server-to-client updates, so status changes in the UI arrive over a persistent connection rather than polling.

## Installing Prowlarr with Docker and adding your first indexer

The README does not contain installation steps. It links to the Servarr wiki for Docker installation (the Docker badge points at wiki.servarr.com/prowlarr/installation/docker), and the project homepage is prowlarr.com. Treat the wiki as the installation source of truth, and check the supported indexers page there before you start, because the built-in list is what determines whether your trackers work out of the box.

The README shows a Docker Pulls badge pointing at the hotio/prowlarr image, so that is the image reference the project itself surfaces. The wiki's Docker page is where the supported Compose and environment variable syntax lives; the README does not spell out a compose file, so take the service definition from there rather than from this article.

Start the container, then open the web UI. The first screen asks you to set authentication, which the wiki covers. After that, add an indexer from the built-in list, or add a Generic Newznab or Generic Torznab entry if yours is not listed, and supply the API key or credentials the tracker gave you.

When the indexer is saved, use the test action in the UI to confirm Prowlarr can reach it. If the tracker sits behind Cloudflare and the test fails, that is the point where you configure a proxy for that indexer. The README lists SOCKS4, SOCKS5, HTTP and Flaresolverr as the supported per-indexer proxy types.

Finally, connect the consuming applications. Add Sonarr, Radarr, Lidarr, Readarr or Mylar3 under the app settings using their URL and API key, and let the indexer sync run. The README also notes that Prowlarr can push multiple releases at once directly to your download clients, so the download client configuration is a separate step from indexer sync.

## Where Prowlarr stops: it is not a downloader, a media server or a search engine

Prowlarr manages indexers and hands releases off. It does not download anything itself in the sense of running a torrent client or a Usenet client, and it does not organise or play media. If your problem is "I want to search trackers and get files", Prowlarr is one component of that pipeline, not the pipeline.

The sync model also has a direction. Prowlarr writes indexer configuration into the connected applications. That is convenient, but it means the connected apps are downstream of Prowlarr for indexer settings. If you have hand-tuned indexer settings inside Sonarr or Radarr that you want to keep, the sync will overwrite that ground, and the README does not document a rollback path for synced indexers. The README is silent on conflict resolution between an existing indexer in Sonarr and the same indexer arriving from Prowlarr.

Native coverage is uneven by design. The README states 24 Usenet indexers natively and over 500 torrent trackers, with "more added all the time". A niche private tracker may not be in either set, and the Generic Newznab or Generic Torznab route assumes the tracker speaks one of those protocols. The README does not promise that every tracker will work through a generic definition.

Finally, the README explicitly says GitHub Issues are for bugs and feature requests only. Support questions belong on the Discord linked in the README or in the wiki. If you file a configuration question as an issue, expect it to be closed.

## Prowlarr compared with Jackett: sync versus a translation layer

The comparison people search for is Prowlarr versus Jackett, and the difference is architectural rather than a matter of feature checklists. Jackett's model is to expose trackers through a Torznab-compatible endpoint that your PVR apps query. You still add an indexer entry in each consuming application, pointing at Jackett, so the configuration exists in two places: the tracker credentials in Jackett, and the indexer entry in Sonarr or Radarr.

Prowlarr inverts that. The README describes indexer sync to Lidarr, Mylar3, Radarr, Readarr and Sonarr with "no per app Indexer setup required". The credentials live in Prowlarr, and Prowlarr writes the resulting indexer configuration into the apps. You manage one list instead of one list plus N indexer entries.

That difference drives the practical trade-offs. Prowlarr's sync only helps if you actually run the applications it names; with a single PVR app the sync has nothing to do, and you are paying the cost of another service for the built-in indexer definitions and the per-indexer proxy support. Prowlarr also brings indexer history and statistics, manual searching at a category level, parameter-based manual searching, and indexer health and status notifications, all listed in the README. Jackett's approach keeps the consuming apps independent, which some people prefer precisely because nothing writes into their Sonarr or Radarr configuration.

## Maintenance, releases and what the GPL-3.0 licence means for you

The repository is not archived. The last push was on 2026-09-16, and the most recent release listed is v2.6.5.5623 on the same date, following v2.6.4.5611 on 2026-09-06 and v2.6.3.5592 on 2026-08-31. That cadence, three releases across roughly two and a half weeks, tells you the project is being cut frequently, which matters for indexer definitions: trackers change their HTML and their domains, and a definition that is not refreshed stops working. Frequent releases are how that maintenance reaches you.

The upgrade cost is mostly operational. If you run the Docker image, you pull a new tag and restart the container. The configuration lives in the volume you mounted for the container, so it survives the restart. The part that needs attention is the connected applications: after an upgrade, verify that indexer sync still reaches Sonarr, Radarr, Lidarr, Readarr and Mylar3, since a changed API or a rotated key on either side breaks the push silently until an indexer fails to return results.

The licence is GNU GPL v3, stated in the README and in the repository LICENSE file, with the copyright line reading 2010-2025. GPL-3.0 is a copyleft licence. If you are only running Prowlarr as a service in your own stack, that is the ordinary use case and the licence is not something you need to think about. If you intend to redistribute a modified Prowlarr, or to ship it inside a product, the copyleft obligations attach to the derivative work. That is a question for your own legal review; nothing here is legal advice, and the LICENSE file is the authoritative text.

## Conclusion

Adopt Prowlarr if you already run two or more PVR apps from the *arr family and are tired of entering the same tracker credentials in each one, or if you want per-indexer proxy support for SOCKS4, SOCKS5, HTTP and Flaresolverr in a single place. Do not adopt it if you run a single PVR app with one or two indexers, since the sync feature has nothing to save you, and do not treat it as a downloader: it hands releases to your download clients but does not replace them. Before committing, read the supported indexers list on the Servarr wiki to confirm your trackers are covered, and check that the application you want to sync to appears in the Lidarr, Mylar3, Radarr, Readarr, Sonarr set, because those are the only sync targets the README names.

## FAQ

### What exactly does Prowlarr do?

Prowlarr is an indexer manager and proxy for Torrent Trackers and Usenet Indexers. It holds the indexer configuration and syncs it to Lidarr, Mylar3, Radarr, Readarr and Sonarr, so you do not configure indexers separately in each of those applications.

### What is the difference between Prowlarr and Sonarr?

Sonarr is the PVR application that manages your series; Prowlarr is the indexer manager that supplies it with indexers. The README lists Sonarr as one of the applications Prowlarr syncs indexer configuration to, not as a component of Prowlarr.

### Is Prowlarr safe to use?

The README does not make a safety claim. What it does show is that Prowlarr stores your tracker credentials and indexer configuration, that you set authentication when you first open the web UI, and that it can route per-indexer traffic through SOCKS4, SOCKS5, HTTP or Flaresolverr proxies.

### What are the key differences between Radarr and Prowlarr?

Radarr manages films; Prowlarr manages indexers. The README names Radarr as one of the applications that receives synced indexer configuration from Prowlarr, alongside Lidarr, Mylar3, Readarr and Sonarr.

### How do I install Prowlarr?

The README does not include installation steps; it points to the Servarr wiki for Docker installation and to prowlarr.com as the homepage. The Docker badge in the README points at the hotio/prowlarr image, and the supported indexers list is on the same wiki.

### How do I use Prowlarr with Flaresolverr?

Flaresolverr is one of the per-indexer proxy types Prowlarr supports, alongside SOCKS4, SOCKS5 and HTTP, according to the README's feature list. You select it for the individual indexer that needs it rather than globally.

## Sources

- [License: GPL-3.0](https://github.com/Prowlarr/Prowlarr/blob/develop/LICENSE)
- [Project website](https://prowlarr.com)
- [Prowlarr/Prowlarr on GitHub](https://github.com/Prowlarr/Prowlarr)
- [README](https://github.com/Prowlarr/Prowlarr/blob/develop/README.md)
- [Releases](https://github.com/Prowlarr/Prowlarr/releases)

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Hysen Labs editorial analysis, written from the project's own repository and release notes. Cite the canonical page: https://hysenlabs.com/projects/prowlarr-prowlarr