Open SSTP Client icon

Open SSTP Client

by KOBAYASHI Ittoku · MIT · open source

An open-source client for SSTP, the VPN protocol that travels over TLS on port 443. It was built for SoftEther VPN servers and the VPN Azure service.

Needs:No root · an SSTP server · Android 6.0+

No known trackers in the code Signer matches IzzyOnDroid’s record

2113 Apps is independent, not affiliated with or endorsed by KOBAYASHI Ittoku. Official sources: source code on GitHub.

Download APK · 5.8 MB v1.10.2 · checked
Version
1.10.2
Size
5.8 MB
Requires
Android 6.0+
Updated
2026-05-02

Screenshots

Open SSTP Client screenshot 1Open SSTP Client screenshot 2Open SSTP Client screenshot 3Open SSTP Client screenshot 4

Introduction

Android has no built-in support for SSTP, a VPN protocol that carries traffic inside a TLS connection on port 443, the port ordinary HTTPS uses. That lets it through most firewalls and proxies. Open SSTP Client fills the gap. Its developer built it for SoftEther VPN Server and the VPN Azure cloud service, and says it hasn’t been tested with other servers.

This is a client only: you need an SSTP server to connect to.

Settings worth knowing

  • Authentication: PAP and MS-CHAPv2, plus EAP-MSCHAPv2 in this version. The README still says EAP isn’t supported, but the option was added in 2024.
  • Certificates: point it at a folder of certificates, and it trusts only those. For a server with a self-signed certificate, the README says to install that certificate on the phone and turn off hostname verification.
  • Per-app rules: choose which apps may or may not use the tunnel. The README recommends turning on Add Default Route along with it.
  • Network: an HTTP proxy, a custom SNI, custom DNS servers and custom routes.
  • Reconnection is off by default. When on, it retries three times, ten seconds apart.
  • Profiles can be saved and loaded from the menu, and a Quick Settings tile connects and disconnects.

Limits

  • The server must have DHCP enabled.
  • The IPv6 option only gives the phone a link-local address; the README doesn’t promise that IPv6 traffic will work.
  • Windows Server isn’t officially supported, although the developer mentions a user who got it working.

Good to know

  • The developer publishes some versions only on Google Play. Play has 1.10.3, whose notes say it just updates dependencies and that there’s no need to update if the app works for you. The file here is 1.10.2, the latest APK released on GitHub.
  • Version 1.10.0 changed how the allowed-apps list and saved profiles are stored. If you use either and came from an older version, the developer asks you to reinstall.
  • The file is 5.8 MB with no native code. It declares seven permissions; one lets it see all installed apps, most likely for the per-app rules.

Written by 2113, last reviewed . Sources: source code, release notes, IzzyOnDroid listing.

What’s inside the APK

Trackers

None found

No code matching the Exodus Privacy tracker signatures.

Native code

None

Pure Java/Kotlin, so it runs on any CPU.

Android versions

Android 6.0 and up

Built for Android 15 (target API 35).

Permissions

7

1 of them need your approval first.

Asks you first (1)

Android shows a prompt before the app can use these.

  • Show notifications (Android 13+) · POST_NOTIFICATIONS
Granted at install (5)

Low-risk permissions Android grants automatically, plus any we have not classified.

  • ACCESS_NETWORK_STATE
  • FOREGROUND_SERVICE
  • FOREGROUND_SERVICE_SPECIAL_USE
  • INTERNET
  • QUERY_ALL_PACKAGES
Defined by other apps (1)

Permissions that belong to another app or to this app itself.

  • kittoku.osc.DYNAMIC_RECEIVER_NOT_EXPORTED_PERMISSION

More Information

Package name
kittoku.osc
Version
1.10.2 (build 49)
File size
5.8 MB (5,848,328 bytes)
Requires
Android 6.0 or later
License
MIT
Developer
KOBAYASHI Ittoku
Released
May 2, 2026
Signer SHA-256
35a0107f1c39134a4ee7c03272fdccb80aac4b864583d063fef63758277de3d5
File SHA-256
eaae3fc3b238d28567a661be6bd57df57aa293bfb2cfeed74cb78397672cb5ca
Checked
, against the IzzyOnDroid index · how we check · verify it yourself

Common questions

Is this APK the official Open SSTP Client release?

Yes. It is the developer’s own release of Open SSTP Client 1.10.2, byte for byte as IzzyOnDroid distributes it. Its SHA-256 matches IzzyOnDroid’s signed index, and it is signed with the certificate IzzyOnDroid records for the app (SHA-256 35a0107f1c39134a4ee7c03272fdccb80aac4b864583d063fef63758277de3d5).

What Android version does Open SSTP Client need?

Android 6.0 or later (API level 23). Version 1.10.2 is built for Android 15 (target API 35). Pure Java/Kotlin, so it runs on any CPU.

Can Open SSTP Client access the internet?

Yes. The APK requests Android’s internet permission. In total it declares 7 permissions, and 1 of them needs your approval first.

Does Open SSTP Client contain trackers?

No known trackers: our scan of version 1.10.2 found no code matching the Exodus Privacy tracker signatures. The scan covers known tracker libraries; it doesn’t show what data the app itself sends.

Is Open SSTP Client open source?

Yes. Open SSTP Client is released under the MIT licence, and its source code is published at https://github.com/kittoku/Open-SSTP-Client.

Recent releases

Version Released Size Requires
v1.10.2 · this download May 2, 2026 5.8 MB Android 6.0+
v1.10.1 Apr 29, 2026 5.8 MB Android 6.0+
v1.10.0 Apr 27, 2026 5.8 MB Android 6.0+

Versions currently kept in the IzzyOnDroid repository. We host and check only the newest one. Full changelog.