The best offline mesh SDKs and tools
If you are choosing how to build offline, peer-to-peer, or mesh connectivity, the honest comparison is form factor against form factor, not vendor against vendor. Some options are SDKs you embed, some are finished apps, some are radio hardware, and one is a gateway network. Below is a factual, side-by-side view of nine options, with a short honest paragraph on each and a link to its detailed page. Offline Protocol is a phone-native software SDK with encrypted mesh, device-owned identity, and serverless service discovery, and it is the right fit for some of these jobs but not all of them.
Diagram: nine alternatives in five shapes, each wired to Offline Protocol, one SDK that covers what every shape is bought for.
Nine alternatives, each built for one shape. Every line lands in the same place. Each name opens its detailed comparison.
How do the nine options compare side by side?
They split by form factor first: SDKs you embed, finished apps, radio hardware, a gateway network, and a sync database.
Covers itPartly, or with conditionsNot part of the product Values reflect each vendor's public documentation. Where a claim is specific, the per-vendor page cites the source.
Values reflect each vendor's public documentation and product claims. Where a claim is specific, the per-vendor pages cite the source. Offline Protocol facts are drawn from its own network: 350,000+ devices reached across 140+ countries.
How should you read this list?
Start with form factor. Meshtastic and goTenna are radio hardware, so the phone is a companion and you distribute devices. Berty and Briar are finished open-source apps for private messaging, not toolkits to build on. Amazon Sidewalk is a gateway network for low-bandwidth IoT that leans on Amazon hardware and internet backhaul. Google Nearby Connections is an Android-first direct-link API, limited to Wi-Fi LAN on iOS, rather than a routed mesh. Ditto is an offline-first database and sync engine. Offline Protocol, Bridgefy, and the SDKs sit in the software-you-embed category, and among those Offline Protocol is the one that adds a routed multi-hop mesh, device-owned identity, and serverless service discovery across iOS and Android.
Which to choose: choose Bridgefy if you need a mobile messaging SDK with a Flutter package on pub.dev today. Choose Ditto if your core problem is an offline-first database that syncs. Choose Meshtastic or goTenna if you need long range and can carry radios. Choose Berty or Briar if you want a finished private messenger rather than an SDK. Choose Amazon Sidewalk for low-bandwidth IoT in the US through Amazon gateways, and Google Nearby Connections for direct links between Android devices in range. Choose Offline Protocol if you are building your own app on phones and need a routed multi-hop mesh with MLS encryption, device identity that verifies with no server, and service discovery. Its mesh SDK is free under AGPL-3.0, local traffic is never metered, and closed-source or App Store apps need the commercial license; see pricing.
Microcontroller protocols such as ESP-NOW are left out, because they run in device firmware rather than in a phone or desktop app. The Learning Center covers them separately, starting with What is an ESP32?
Read the platform overview for how the shipped layers fit together, or use the summaries below to jump into a detailed comparison.
What is each option, in brief?
Offline Protocol
An open-source SDK and coordination layer for building offline-capable products, free under AGPL-3.0 with a commercial license for closed-source and App Store apps. It meshes the phone radios over BLE, WiFi Direct, and internet with automatic failover and 8-hop relay, and adds MLS (RFC 9420) encryption, an Ed25519 OfflineID for device identity with no server, and serverless service discovery. It is a Rust core with a React Native binding, with 350,000+ devices reached across 140+ countries. Best fit when you are building a product that needs a routed mesh with identity and discovery, not a finished app or a database.
See all comparisons →Ditto
An offline-first database with a built-in peer-to-peer sync engine that uses CRDTs to merge data across devices over Bluetooth, LAN, and peer-to-peer WiFi, with the server optional (ditto.com). Best fit when your core problem is conflict-free replication of a shared dataset. It is a data layer, so it often complements a connectivity layer rather than competing with one.
Compare with Ditto →Bridgefy
A phone-native mesh SDK that relays messages over Bluetooth and WiFi Direct with Signal Protocol end-to-end encryption. Best fit when you want a mobile messaging mesh on the phones people already carry. It is closest to Offline Protocol on form factor, so the per-page comparison focuses on encryption, identity, and coordination.
Compare with Bridgefy →Meshtastic
An open-source LoRa mesh built on inexpensive radio hardware with open firmware, using channels rather than per-user identity. Best fit for hobbyists and off-grid users who can carry a radio. Choose a phone-native software mesh instead when you cannot ship a device to every user.
Compare with Meshtastic →goTenna
Hardware mesh radios, the goTenna Pro and ProX line, that pair to a phone app over a proprietary radio for off-grid messaging and location sharing. Best fit for long single-link range across sparse terrain when users can carry a dedicated radio. A software SDK fits better when distribution is app-only.
Compare with goTenna →Berty
An open-source, privacy-first peer-to-peer messaging app built on the Wesh protocol, a libp2p-based stack over BLE and the internet, with no phone number and no central server (berty.tech). Best fit as a self-contained private messenger. It is an app and protocol, not a commercial SDK with offline identity and service discovery for embedding in a product.
Compare with Berty →Briar
An open-source secure messenger aimed at activists and journalists, with peer-to-peer messaging over Bluetooth, WiFi, and Tor, a store-and-forward design, and a focus on Android (briarproject.org). Best fit for resilient private messaging as a finished app. It is a consumer messenger, not an SDK for embedding mesh into your own product.
Compare with Briar →Amazon Sidewalk
A shared, low-bandwidth network that uses BLE and 900 MHz radio, including LoRa, with Amazon Echo and Ring devices as gateways that bridge to the internet, and it is US-centric (amazon.com). Best fit for connecting low-bandwidth IoT devices through existing Amazon gateways. It depends on gateway hardware and internet backhaul, unlike a phone-native mesh.
Compare with Amazon Sidewalk →Google Nearby Connections
Google's API for peer-to-peer connectivity between nearby devices, over Bluetooth, BLE, and WiFi on Android, with an iOS library limited to Wi-Fi LAN (developers.google.com). It establishes direct links between nearby devices rather than a multi-hop routed mesh, and leaves identity and higher-level discovery to the app. Best fit when Android devices in direct range need to exchange data without the internet.
Compare with Google Nearby Connections →Choosing an offline mesh SDK
Which offline mesh SDK should I choose?
Choose Bridgefy if you need a mobile messaging SDK with a Flutter package on pub.dev today. Choose Ditto if your core problem is an offline-first database that syncs between devices. Choose Meshtastic or goTenna if you need long range and your users can carry radios. Choose Berty or Briar if you want a finished private messenger rather than an SDK. Choose Amazon Sidewalk for low-bandwidth IoT in the US through Amazon gateways. Choose Google Nearby Connections for direct links between Android devices in range. Choose Offline Protocol if you are building your own app on phones and need a routed multi-hop mesh with MLS encryption, device identity that verifies with no server, and service discovery.
Which of these are free, and what does Offline Protocol cost?
Meshtastic firmware (GPL-3.0), Berty (Apache-2.0 or MIT), and Briar (GPL-3.0) are free open-source projects, and Google Nearby Connections is open source under Apache-2.0 with no published fee. Bridgefy and Ditto are proprietary SDKs with plans on their own pricing pages, goTenna sells radios through its sales team, and Amazon Sidewalk device makers pay AWS IoT Core message fees. The Offline Protocol mesh SDK is free under AGPL-3.0-only, including in production, and local mesh traffic is never metered. Closed-source apps and apps distributed through the Apple App Store need the commercial license, which has no published price, so contact us for pricing. Hosted services are optional and run on Free ($0), Pro ($99 a month), Scale ($499 a month), and Enterprise plans. See Offline Protocol pricing.
