Postman vs Insomnia vs Bruno: The Best API Testing Tool for Developers in 2025

If you’ve written a single line of backend code in the last decade, you’ve likely hit Ctrl+Enter inside Postman. For years, it was the undisputed king of API testing. But the landscape has shifted. By late 2024, Postman’s cloud-based collaboration push, Insomnia’s acquisition by Kong, and the rise of Git-native tools like Bruno have created a genuine three-way split in developer preference.

According to the 2024 Stack Overflow Developer Survey, over 25% of professional developers use Postman daily, but a growing cohort—particularly those working in Git-centric, security-conscious environments—is actively migrating to alternatives. The question isn’t “which tool is the most popular” anymore. It’s “which tool fits your specific workflow without getting in your way.”

Here’s a data-driven breakdown of Postman, Insomnia, and Bruno to help you decide which client deserves a place in your IDE-adjacent toolkit in 2025.

The Contenders at a Glance

Before we dive into the weeds, let’s establish the baseline identities:

  • Postman: The enterprise juggernaut. Cloud-first, feature-rich, and collaboration-heavy.
  • Insomnia: The developer-focused designer. Owned by Kong, it excels at REST and GraphQL design with a cleaner, local-first UI.
  • Bruno: The Git-native disruptor. Stores collections as plain text files on your filesystem, eliminating the need for a cloud account entirely.

Postman: The Feature-Rich Industry Standard

Postman is not just a tool; it’s a platform. With over 20 million registered users and 500,000+ public APIs in its network, it remains the default choice for most teams, and for good reason.

Strengths

  • Unmatched Ecosystem: Postman offers built-in support for REST, GraphQL, gRPC, and WebSocket protocols. You can write pre-request scripts and test suites in JavaScript (Node.js sandbox), run API tests in CI/CD via Newman, and generate production-ready code snippets for 20+ languages (including Python, Go, and JavaScript).
  • Collaboration at Scale: The cloud-based workspace model allows teams to share collections, environments, and mock servers in real-time. For enterprise teams, this is a killer feature. You can comment on specific requests, tag teammates, and maintain role-based access control (RBAC).
  • AI Assistance: In 2024, Postman integrated Postbot, an AI assistant that can write test assertions and debug failed requests. It’s not perfect, but it reduces the boilerplate time for writing common checks like status code validation or JSON schema verification.

Weaknesses

  • Blatant and Growing: The UI is now a dense marketplace. The free tier is limited to 3 collaborators per workspace, and features like API monitoring, mock servers, and full test history are locked behind the paid tiers ($12–$24 per user/month). For solo developers, this feels like being forced to use a CRM to send a single email.
  • Performance Overhead: The Electron-based app is notoriously memory-hungry. On a 16GB RAM MacBook Pro, running Postman alongside Docker and VS Code can cause significant lag, especially with large collections (1,000+ requests).

Best For

  • Enterprise teams that need centralized governance, audit logs, and cross-functional collaboration (QA, Dev, Product).
  • Developers who need a one-stop-shop for mocking, testing, and documenting APIs without juggling multiple tools.

Insomnia: The Designer’s Choice

When Kong acquired Insomnia in 2023, there was a lot of hand-wringing about its future. However, the 2024 releases (v9 and v10) have doubled down on the developer experience, focusing on speed and design.

Strengths

  • Superior Request Composer: Insomnia’s UI is arguably the cleanest of the three. The environment variables system is more intuitive, and the ability to leverage Nunjucks templating for dynamic request bodies is a massive time-saver for complex workflows.
  • GraphQL First-Class Support: If you work with GraphQL APIs, Insomnia is still the gold standard. The built-in GraphQL client allows you to auto-generate queries, manage fragments, and inspect the schema directly within the editor. Postman added GraphQL support, but Insomnia’s implementation is more fluid.
  • Local-First Data: Unlike Postman, Insomnia stores your data locally by default. You can opt-in to sync via Insomnia Cloud or self-hosted Kong Gateway, but you aren’t forced into it. This is a significant privacy win for developers working on proprietary APIs.
  • Unit Testing: Insomnia’s testing framework is lighter than Postman’s but integrates directly with insomnia-testing CLI. It’s simpler to write and debug, particularly for developers who prefer writing tests in a familiar syntax.

Weaknesses

  • Weaker Collaboration: The collaboration features are functional but feel bolted on. The “Collection Sync” requires a paid subscription (InSomnia Plus at $5/user/month), and the interface for reviewing teammates’ changes is clunky compared to Postman’s activity feed.
  • Fewer Integrations: While it has a solid plugin ecosystem, it lacks the deep third-party integrations Postman offers (e.g., Azure DevOps, AWS API Gateway, Salesforce).

Best For

  • Solo developers and small teams who prioritize UI speed and local data privacy.
  • GraphQL-heavy frontend teams who need to iterate quickly on schema design.

Bruno: The Git-Native Rebel

Bruno is the new kid on the block, but it’s growing fast—it hit 15,000+ GitHub stars within months of its open-source release in late 2023. Its core philosophy is radical: your API collection is just a folder of Markdown and text files.

Strengths

  • Git-Native Workflow: Bruno stores every request as a .bru file (plain text). This means you can version your API collections in Git, review changes in pull requests, and resolve merge conflicts like you would with code. No more exporting JSON files or fighting over who changed the environment variables.
  • No Account Required: There is no login, no cloud sync, and no telemetry. You download the app, and it works offline. For developers in regulated industries (finance, healthcare) or those working on air-gapped networks, this is a game-changer.
  • Performance: Because it’s built on Electron but doesn’t run a background cloud sync service, it feels snappier than Postman. Startup time is significantly faster.
  • Transparent Pricing: The core app is free, and the paid “Pro” tier ($19 one-time payment) only adds features like Git integration wizards and collection-level scripting. There is no recurring subscription model, which is a breath of fresh air.

Weaknesses

  • Immature Ecosystem: It lacks the depth of Postman’s scripting library. While it supports JavaScript (Node.js) for pre-request scripts and assertions, the API is limited. Complex workflows like OAuth2 token refresh loops require manual coding that is harder to debug than in Postman.
  • No Native Cloud Features: There are no mock servers, no API documentation hosting, and no cloud-based monitors. You can run tests via CLI (bru run), but you need to set up your own CI pipeline for that.
  • Smaller Community: You won’t find as many Stack Overflow answers or blog posts for niche issues. You’ll often need to read the source code or submit GitHub issues.

Best For

  • Git-centric teams that treat API definitions as code and want to eliminate cloud sync overhead.
  • Security-conscious developers who refuse to send request data to third-party servers.

Head-to-Head: The 2025 Comparison Matrix

Feature Postman Insomnia Bruno
Pricing (Solo) Free (limited) / $12+ /mo Free / $5+ /mo Free / $19 one-time
Data Storage Cloud-first Local-first Local-first (Git)
Protocol Support REST, GraphQL, gRPC, WebSocket REST, GraphQL, WebSocket REST, GraphQL (basic), WebSocket
Scripting Node.js (Extensive) Node.js (Moderate) Node.js (Limited)
Collaboration Excellent (RBAC, comments) Good (Paid sync) Excellent (via Git PRs)
Offline Mode Limited Yes Yes
AI Features Postbot (Built-in) No No
Best For Enterprise & Full-feature UI/UX & GraphQL Git-native & Privacy

The Verdict: Which One Should You Use in 2025?

There is no single “best” tool; there is only the best tool for your specific constraints.

  • Choose Postman if you work in a team of more than five people where non-developers (QAs, product managers) need to inspect requests. The collaboration and governance features justify the cost and the bloat. If you need to generate API documentation or mock servers without setting up separate infrastructure, Postman is still the fastest path.

  • Choose Insomnia if you are a solo full-stack developer or work in a small startup where developer experience (DX) is paramount. If you live in GraphQL or need a tool that opens instantly and doesn’t nag you to log in, Insomnia is the sweet spot. The Kong integration also makes it a natural fit if you’re already using Kong Gateway.

  • Choose Bruno if you are a developer who believes API collections should live in the same repository as your backend code. If you value version control, code reviews for API changes, and absolute data privacy, Bruno is the forward-looking choice—even if it means sacrificing some advanced automation features today.

The Bottom Line: In 2025, the era of “one tool for everything” is over. Postman is still the safe default, but it’s no longer the smart default. Evaluate your workflow, check your budget, and don’t be afraid to keep two tools installed—many developers now use Bruno for local development and Postman for the occasional enterprise handoff.