Every backend and frontend developer ends up with one app permanently open next to the editor: the API client. It is where you build requests, inspect responses, debug the 401 that only happens on staging, and run the test suite against the collection before a release. Choosing it is a real decision — you will spend hundreds of hours in it.
This guide compares the clients developers actually shortlist in 2026: Postman, Insomnia, Bruno, Hoppscotch and our own Apiboo Workspace. Yes, we make one of the tools on this list — so we have kept the criteria objective and we say plainly where each competitor is the better pick.
What actually matters in a REST API client
Feature checklists all blur together. In practice, five questions separate the tools:
- Protocols: REST is table stakes — do you also get GraphQL, WebSocket, SSE and gRPC when a project needs them?
- Where your data lives: on your machine, in a vendor’s cloud, or in Git? Who can read your collections and secrets?
- Auth depth: OAuth 2.0 with PKCE, AWS Signature v4 and mTLS client certificates are where lightweight clients tap out.
- Team workflow: how do two people edit the same collection — real-time sync, cloud workspaces, or pull requests?
- Total tool count: does the client cover mocking, docs, testing and the conversation around the work, or does each of those need another subscription?
Postman — the default, and the heaviest
Postman is the incumbent for a reason: an enormous feature surface, cloud workspaces, monitoring, governance, a public API network and a huge community. If you publish public APIs at scale, its ecosystem is unmatched.
The trade-offs are just as well known. Since the offline Scratchpad was retired, sign-in and cloud sync are the expected path, which turns your collections into a data-governance question. The app is heavy, the deeper platform features sit in paid tiers, and per-user pricing adds up quickly for teams that only need the client.
Insomnia — the focused designer’s client
Kong’s Insomnia remains a clean, capable client with genuine strengths: a design-first workflow around OpenAPI, solid GraphQL and gRPC support, and — after the 2023 backlash — local, Git or cloud storage you choose per project.
What it deliberately does not do is the rest of the workflow: no boards, no chat, no database tooling. And its direction is set by an API-gateway company, which is either reassuring or concerning depending on your stack.
Bruno — Git-native and open source
Bruno stores collections as plain-text .bru files in your repo, works entirely offline, and has an MIT-licensed core. For solo developers and small teams who want collections reviewed like code, it is a genuinely great design, and if open source is a hard requirement it is the pick on this list.
The Git-only model is also its ceiling: environment changes are commits, secrets management is your problem, there are no built-in mock servers, and team workflows route through pull requests.
Hoppscotch — the browser-first option
Hoppscotch runs in a browser tab, is open source, and can be self-hosted. As a quick, zero-install client for trying an endpoint — or as a self-hosted tool inside a locked-down org — it is excellent, and it has grown real REST, GraphQL and WebSocket depth.
A browser tab has limits a desktop app does not: interception of some auth flows, client certificates, and working against local services can be fiddlier, and the offline story depends on how you deploy it.
Apiboo Workspace — the all-in-one, local-first workspace
Apiboo Workspace is our entry, and its bet is different: keep the local-first privacy Bruno users care about, match the serious client features Postman users rely on, and then bundle the tools around the API work that every other client leaves to separate apps.
Concretely: REST, GraphQL, WebSocket, SSE and gRPC; OAuth 2.0 with PKCE, AWS Signature v4 and mTLS; environments with variable scopes; pre-request and test scripts with a collection runner; local and cloud mock servers; and code generation for cURL and 8 languages. Around the client: Kanban task boards, team chat with an AI assistant that can build and run requests, a database manager for MySQL, PostgreSQL and SQLite, OpenAPI docs generated from collections, and rich-text docs with PDF export. Everything is stored locally by default with an end-to-end encrypted personal vault for secrets, works offline, and syncs in real time only when you turn it on. It is built in the EU — data home on EU infrastructure, with a US edge region for latency — GDPR-compliant, and free to start.
The honest caveat: Apiboo is the youngest tool on this list, and it is a commercial product, not open source. If you need a decade-deep ecosystem or an MIT license, look above.
Which one should you choose?
A short decision guide:
- You publish large public APIs and live in cloud workspaces → Postman.
- You want a focused, design-first client with flexible storage → Insomnia.
- Open source and collections-in-Git are hard requirements → Bruno.
- You want zero-install or self-hosted in the browser → Hoppscotch.
- You want one local-first app that covers the client plus boards, chat, docs and your database → Apiboo Workspace.
Try the migration, not the marketing
Every serious client imports the others’ formats now — Apiboo imports Postman, Insomnia, Bruno, OpenAPI, HAR and cURL directly. The cheapest way to decide is to import your real collection into a candidate and run your actual workflow for a day. Marketing pages (this one included) are no substitute for your own staging environment returning a 403 at 5 pm.