Postman alternative: a native, privacy-first API client
If you are looking for a Postman alternative, the two complaints that usually trigger the search are the same: it feels heavy, and it wants your data in the cloud. Dev Calls answers both — it is a native desktop API client built with Kotlin Multiplatform, with no Electron runtime and local-first storage.
Native performance instead of a bundled browser
Postman ships as an Electron app, which means every window carries a full Chromium runtime. Dev Calls renders through Compose Multiplatform directly on the platform toolkit: the UI runs at 120fps, cold startup is near-instant, and memory stays roughly 90% lower than Chromium-based clients on the same workspace.
In practice that is the difference between an API client you leave open all day and one you close to get your laptop fan back.
Privacy first: no mandatory account, no cloud tracking
Dev Calls stores collections, environments and tokens on your machine. There is no sign-in wall to send a request, and no telemetry pushing your endpoints to a vendor. Sync is opt-in and end-to-end encrypted, so teams that need shared workspaces still keep the payloads private.
No Electron — where the memory goes
Electron-based clients pay for a browser engine, a Node process and a renderer per window before a single request is sent. Dev Calls has one native process. That single architectural choice is what makes the startup, scrolling of large responses, and long-lived WebSocket or SSE sessions feel immediate.
Dev Calls vs Postman at a glance
| Dev Calls | Postman | |
|---|---|---|
| Runtime | Native (Compose Multiplatform) | Electron / Chromium |
| Cold startup | Near-instant | Several seconds |
| Memory usage | ~90% lower | Hundreds of MB idle |
| Account required | No | Yes for most features |
| Data storage | Local-first, optional E2E sync | Cloud-synced by default |
| Protocols | REST, GraphQL, WebSocket, SSE, gRPC | REST, GraphQL, WebSocket, gRPC |
| Collection import | Postman v2.0 / v2.1 one-click | Native |
| Platforms | Windows, macOS, Linux | Windows, macOS, Linux |
Migrating from Postman
- Export your Postman collections (v2.0 or v2.1) and environment files.
- Import them into Dev Calls in one click — folders and variables are preserved.
- Pick the environment you need and start sending requests; nothing leaves your machine.
Postman alternative FAQ
- What is the best Postman alternative for low memory usage?
- Dev Calls is built with Kotlin Multiplatform and Compose Multiplatform instead of Electron, so it renders natively and typically uses around 90% less memory than Chromium-based API clients.
- Can I import my Postman collections into Dev Calls?
- Yes. Dev Calls supports one-click import of Postman v2.0 and v2.1 collections and environment files, so you can migrate without rebuilding requests.
- Does this Postman alternative require an account?
- No. Dev Calls is local-first: your requests, environments and secrets stay on your machine, with no mandatory account and no cloud tracking.
- Is Dev Calls free?
- Dev Calls is free for individual developers. Team collaboration features are available on a paid plan.