The Best Messenger for Iran When the Internet Is Blocked

If you are looking for a messaging app that keeps working in Iran when platforms are blocked or connections slow to a crawl, this guide explains what to look for, how OSHI can help, and which other trusted tools are worth having installed alongside it.

The connectivity picture in Iran

Iran has one of the world's most tightly managed internet environments. Access to many international messaging and social platforms is filtered, and users routinely rely on VPNs and circumvention tools to reach blocked services. During periods of unrest, authorities have repeatedly slowed mobile data or restricted connectivity, and the country has invested for years in a domestic National Information Network intended to keep local services running even when the international internet is curtailed.

For people inside Iran, the practical consequences are familiar: apps that worked yesterday may be unreachable today, VPNs that connected this morning may be blocked by evening, and recognizable encrypted-messenger traffic can be throttled or filtered even when its contents stay private. This is exactly the environment mesh and steganographic tools are designed for — keeping messages moving when ordinary channels are unreliable.

What matters when you message from Iran

Not every feature is equally useful in Iran. These are the properties that make the real difference under filtering, throttling, or shutdowns:

• ✓Offline mesh networking. When mobile data or Wi-Fi is throttled or cut, OSHI can still relay messages device-to-device over Bluetooth Low Energy and local Wi-Fi. Phones near each other form a peer-to-peer mesh, so a message can hop between people even with no working internet connection.
• ✓No phone number required. Registering with a SIM ties your identity to a real name in most Iranian networks. OSHI identities are cryptographic keys generated on your device, so there is no phone number to seize, SIM-swap, or subpoena.
• ✓Tor routing and covert channels. For online delivery, OSHI can route through Tor and hide traffic inside ordinary-looking web requests using steganographic covert channels — useful where deep packet inspection (DPI) fingerprints and blocks recognizable messenger traffic.
• ✓Signal-protocol-style end-to-end encryption. X25519 key exchange, AES-256-GCM, and the Double Ratchet mean only you and your contact can read a message — the server never can.
• ✓Open source and auditable. The full source is public on GitHub under the MIT license, so anyone can verify there are no backdoors.

How OSHI helps — and where it does not

OSHI was built for exactly this kind of environment. Online, it can route through Tor and disguise traffic inside ordinary-looking web requests, which makes recognizable-messenger blocking harder to apply. Offline, its Bluetooth and Wi-Fi mesh keeps messages moving between nearby people when the internet is throttled or cut. Because it needs no phone number and stores nothing readable on the server, there is very little metadata for anyone to collect. And because it is open source under the MIT license, its security claims can be independently verified rather than taken on trust.

OSHI vs other tools for Iran

OSHI is not the only good option, and no single tool is right for everyone. Choosing the right one depends on your threat model, who you need to reach, and what the network looks like where you are.

Signal is the gold standard for everyday secure messaging: a mature, heavily audited codebase, disappearing messages, and reliable voice and video. Its main limitations in censored environments are that it requires a phone number and needs a working internet connection — and its traffic can be fingerprinted and blocked, though Signal offers censorship-circumvention proxies. Briar is the closest philosophical relative to OSHI: it is peer-to-peer, routes over Tor by default, syncs over Bluetooth and Wi-Fi when the internet is down, and needs no phone number. Briar is Android-only, which matters if you or your contacts use iPhones. Bridgefy popularized Bluetooth mesh chat during large protests; it is simple and works offline, but its security model has historically been weaker than Signal-protocol messengers, so treat it as a broadcast/coordination tool rather than a confidential one. Tor (via Orbot on mobile) is not a messenger at all — it is a transport layer that many of these tools can ride on to reach the open internet.

A realistic setup often combines tools: a mesh-capable messenger such as OSHI or Briar for when the network is cut, plus Signal for high-reliability contact with people abroad when you do have connectivity. Redundancy is the point.

Frequently Asked Questions