SimpleX Chat

Free plan Open source AndroidAPIiPhoneLinuxMacSelf-hosted+1

What SimpleX Chat is

SimpleX Chat is a free messaging application built on the SimpleX platform, available for Android, iOS, Linux, macOS, and Windows. It supports encrypted messages with Markdown and editing, media and file sharing, decentralized groups, voice messages, disappearing messages, and audio and video calls. The network assigns no user profile identifiers, including phone numbers or usernames. Messages and metadata use end-to-end encryption with continuous post-quantum key exchange. Each chat uses four servers, arranged so relay servers cannot see which IP addresses are communicating. Profiles, contacts, and messages are kept in a portable encrypted database on client devices; relay servers temporarily retain encrypted messages until delivery. Users can run their own SimpleX servers while still communicating with users of preconfigured servers. Developers can use protocol SDKs for bots and integrations, including a TypeScript SDK that connects to the CLI through a WebSocket API. Linking a mobile device to the desktop app requires both devices to be on the same local network.

Who it suits

SimpleX Chat may suit people seeking messaging without network-assigned profile identifiers and with end-to-end encryption. Developers can also use its protocol SDKs for bots and integrations.

What it does well

Available on Android, iOS, Linux, macOS, and Windows.
Network assigns no user profile identifiers.
Messages and metadata use end-to-end encryption.
Users can run their own servers.
Supports audio and video calls.

What to know first

Mobile-to-desktop linking requires the same local network.
Deletion on recipients' devices is not guaranteed in some cases.
No encrypted backups are listed.

Plans

Plan	Billed and limits	Price
SimpleX Chat	everything free; paid features planned	Free
Free	Free · No subscription charge stated	Free

As simplex.chat lists them, read 1 Oct 2026. The maker's own page has the final word.

Getting started

Visit https://simplex.chat/.
Download the app for iOS or Android, or the desktop version for Linux, macOS, or Windows.
Create a profile and connect with contacts using the app’s messaging features.
To link a mobile device to desktop, connect both devices to the same local network.
If you want to host servers, run your own SimpleX servers; they can still communicate with users on preconfigured servers.

Verdict

SimpleX Chat pairs identifier-free network design with messaging, groups, and calls across mobile and desktop platforms. Note the local-network requirement for desktop linking and the limits on ensuring deletion from recipients' devices.

Questions

How much does SimpleX Chat cost?

The SimpleX Chat plan is free, and everything is free.

Which platforms does it support?

Mobile apps are available for iOS and Android, and desktop downloads are available for Linux, macOS, and Windows. The listed platform options also include API and self-hosted.

Does it support voice and video calls?

Yes. The apps support audio and video calls, as well as voice messages.

Can I host my own SimpleX servers?

Yes. Users can run their own servers and still communicate with users on preconfigured servers.

Can a mobile device link to the desktop app from any network?

No. Both devices must be connected to the same local network to link.

Are disappearing messages guaranteed to be deleted from recipients’ devices?

No. Disappearing messages and full deletion cannot be guaranteed or enforced if a recipient’s device is offline or runs modified software.

Facts from SimpleX Chat's own pages

API and SDK: The open SimpleX protocol includes an SDK for building chat bots and services that users access through SimpleX Chat apps. · simplex.chat, 14 Oct 2026
Audio and video calls: The platform supports end-to-end encrypted audio and video calls and can use self-hosted WebRTC relays. · simplex.chat, 14 Oct 2026
Company identity: Crunchbase identifies the legal name as SimpleX Chat, Inc., founded in 2021, with headquarters in London, England, and founder Evgeny Poberezkin. · crunchbase.com, 14 Oct 2026
Company size: LinkedIn lists SimpleX Chat as a privately held technology company with 2–10 employees. · linkedin.com, 14 Oct 2026
Company status: SimpleX Chat Ltd is a UK-registered company developing communication software for the SimpleX network. · simplex.chat, 1 Oct 2026
Crowdfunding news: SimpleX announced an equity crowdfunding round on Wefunder on August 20, 2026, stating that the app had exceeded three million downloads and about 480,000 monthly users. · simplex.chat, 14 Oct 2026
Data storage: Profiles, contacts and messages are stored on client devices in a portable encrypted database, while relay servers temporarily hold encrypted messages until delivery. · simplex.chat, 1 Oct 2026
Deletion limitation: Message deletion and disappearing-message behavior cannot be guaranteed on recipients’ devices if they are offline or run modified software. · simplex.chat, 14 Oct 2026
Desktop linking limit: A mobile device can link to the desktop app only when both devices are connected to the same local network. · simplex.chat, 1 Oct 2026
Developer documentation: Documentation covers protocol schemas, terminal CLI operation, relay deployment, chat relays, calls, channels, privacy, and security settings. · simplex.chat, 14 Oct 2026
Developer integrations: The open protocol provides SDKs for chat bots and integrations, including integration of the SimpleX Chat library into mobile apps. · simplex.chat, 1 Oct 2026
Disappearing messages: Chats support disappearing messages with opt-out controls per contact or group. · play.google.com, 14 Oct 2026
Download requirements: Official desktop builds include Linux AppImage or Flatpak, Ubuntu 22.04/24.04 and Debian-based systems, macOS Intel or Apple Silicon, and Windows x86_64. · simplex.chat, 14 Oct 2026
Encrypted media: Users can send encrypted images and files, plus encrypted voice messages of up to five minutes. · play.google.com, 14 Oct 2026
Encrypted portable database: The app stores an encrypted portable chat database that can be transferred with contacts and history to another supported device. · apps.apple.com, 14 Oct 2026
Encryption: The network uses end-to-end encryption with continuous post-quantum key exchange for messages and metadata. · simplex.chat, 1 Oct 2026
End-to-end encryption: Messages, files, voice messages, and calls are end-to-end encrypted so relay servers cannot decrypt their content. · shieldcue.com, 14 Oct 2026
Funding: SimpleX announced a $1.3 million pre-seed round led by Jack Dorsey with participation from Asymmetric Capital Partners in August 2024. · simplex.chat, 14 Oct 2026
Headquarters: London, United Kingdom · simplex.chat, 28 Sept 2026
Independent score: ShieldCue rates SimpleX Chat 9.2 out of 10 and describes it as free, open source, and end-to-end encrypted. · shieldcue.com, 14 Oct 2026
Independent security findings: PrivacyPick reports that the 2024 design review found three medium- and one low-severity issues, characterized as difficult to exploit. · privacypick.com, 14 Oct 2026
License: The application source code is available under the GNU Affero General Public License version 3. · simplex.chat, 14 Oct 2026
Limit: iOS usability: Apple reviewers repeatedly report awkward or outdated interface design, freezes, crashes, and other iOS usability bugs. · apps.apple.com, 14 Oct 2026
Limit: notifications: Apple and Google reviewers report delayed or missing background notifications and messages that arrive only after opening the app. · apps.apple.com, 14 Oct 2026