Feather vs Scarlet iOS: Which On-Device Signer to Use in 2026

ByScarlet iOS Team Updated on

Feather is a free, open-source on-device signer that many former ESign users moved to. Scarlet iOS is an on-device installer that provides the certificate for you. Both install IPA files on an iPhone without a computer or a jailbreak, but they are built for different people. This guide compares them on certificates, setup, features, iOS support and safety. Last checked: October 27, 2026. Feather facts are from its own GitHub project page (version 2.9.0, July 2026).

Short Answer

Choose Scarlet iOS if you do not have your own Apple developer certificate: Scarlet provides one, so you can start installing apps right away. Choose Feather if you have your own certificate from the Apple Developer Program and want a transparent, open-source signer: it is built for exactly that and does not supply certificates itself.

What Is Feather?

Feather describes itself as a “free on-device iOS/iPadOS application manager/installer, using certificates part of the Apple Developer Program”. It is made by the developer known as claration (also behind the computer tool Impactor), licensed under GPL-3.0, and published on GitHub, where it had about 4,900 stars in October 2026. Its listed features are:

  • signing and installing apps on the device
  • support for AltStore-format repositories
  • detailed information about apps and your certificates
  • signing options to modify apps, such as appearance and Files app support, including patches for compatibility and Liquid Glass
  • tweak injection for advanced users (.deb and .dylib files, using ElleKit)
  • no tracking or analytics

It needs iOS 16 or later. The project’s own page says it is “meant for developer certificates”, so you need a .p12 certificate and its provisioning profile to use it (see p12 and mobileprovision files explained).

What Is Scarlet iOS?

Scarlet iOS is an on-device app installer with a built-in app library and support for third-party repos. It signs apps with a certificate that Apple accepts, which it provides, so you do not need a developer account. You trust its developer profile once in Settings > General > VPN & Device Management. Scarlet is confirmed to work on iOS 14 through iOS 26; iOS 27 support has been reported by third parties but is not officially confirmed. You can get it from our Scarlet iOS install page.

Certificates: The Main Difference

  • Scarlet iOS: the certificate comes with Scarlet. That makes it easy to start, but the certificate is shared with many users, so Apple can revoke it. When that happens, Scarlet and the apps it installed stop opening until they are signed again; see our guide on what to do when the Scarlet certificate is revoked.
  • Feather: you bring your own certificate. With a paid Apple Developer Program membership (99 US dollars a year from Apple), the certificate is yours, so other people’s use cannot get it revoked. Apps signed with it run until the certificate or its provisioning profile expires.

Some people use Feather with free certificates shared in Telegram groups. Those are other people’s certificates used by thousands of devices, so Apple usually revokes them quickly, and you are trusting whoever controls them. If you do not have your own certificate, Scarlet is the simpler and more honest choice.

Setup

  • Scarlet iOS: install it from the install page, trust the developer profile once, and open it. No computer needed.
  • Feather: download Feather.ipa from the project’s GitHub releases. Because Feather does not come with a certificate, the first install has to be signed some other way, for example with your own certificate on a computer. The project points to Impactor, its sibling open-source computer tool for macOS, Windows and Linux, which also helps create the pairing file Feather can use for installing. After that, you import your .p12 and provisioning profile into Feather and sign on the device.

Features Compared

Feature Scarlet iOS Feather
Certificate Provided Bring your own
Cost Free Free (certificate extra)
Open source No Yes, GPL-3.0
Repos Built-in library + repos AltStore-format repos
Tweak injection Yes Yes (.deb, .dylib)
iOS support iOS 14 to 26 confirmed iOS 16 and later
Revoke risk Shared certificate Only your own certificate

Repos and Apps

Scarlet reads its own repo format and ships with a built-in library, and large repos such as AppTesters publish in a format it reads directly. Feather reads AltStore-format sources, the format used by many open-source projects and emulators. A repo works in both only if it publishes both formats, so check the repo’s own page. Our list of the best IPA libraries and repositories for 2026 notes the format and the risk of each source.

Safety

  • Feather: the code is public, there is one official download (GitHub releases), and the project states it has no tracking or analytics. Download it only from the GitHub page; copies on re-upload sites cannot be checked.
  • Scarlet iOS: closed source, with an official install page. The main practical risk is a certificate revoke, not data collection, and that is a limit of the shared-certificate method.
  • Both: the signer does not make an app safe. A modified IPA from an unknown source carries the same risk in either tool. Read is iOS sideloading safe before you install apps from new sources.

Feather, KSign and ESign

ESign, the closed-source signer Feather is often compared with, is described as end of service by the KSign project. KSign is built on Feather and recreates ESign’s look, so ESign users feel at home; see KSign for iPhone. Feather is the base project. See our Scarlet iOS vs ESign comparison for the full background.

When to Use Which

Choose Scarlet iOS if:

  • you do not have an Apple developer certificate
  • you want to install apps from a built-in library in a few taps
  • you are new to sideloading
  • your iPhone runs iOS 14 or 15, which Feather does not support

Choose Feather if:

  • you have your own Apple Developer Program certificate
  • you want an open-source signer you can inspect
  • you want detailed signing options and tweak injection
  • you mainly use AltStore-format sources

Some people use both: Scarlet for quick installs from its library, and Feather for the apps they sign with their own certificate. For the bigger picture of on-device tools, see the free sideloading tools compared.

FAQ

Is Feather free?

Yes. Feather is free and open source (GPL-3.0). What costs money is the certificate: Apple’s Developer Program is 99 US dollars a year.

Can I use Feather without a certificate?

No. Feather is meant for developer certificates and does not provide one. Scarlet iOS is the option that comes with a certificate.

Does Feather work on iOS 26?

Yes. Feather needs iOS 16 or later, and its 2026 releases were built with the iOS 26 SDK and added Liquid Glass support.

Where do I download Feather safely?

Only from the project’s GitHub releases page (github.com/claration/Feather). Other download sites are re-uploads you cannot verify.

Can Scarlet and Feather be on the same iPhone?

Yes. They are separate apps with separate certificates, so one does not affect the other.

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