Postman vs Insomnia vs Thunder Client: Which API Client Is Best for Developers in 2024

Postman vs Insomnia vs Thunder Client: Which API Client Is Best for Developers in 2024

A 2023 Stack Overflow survey of more than 90,000 developers found that roughly 60% work with APIs at least weekly, and the tools they reach for have quietly become as personal as their code editors. Three names dominate the conversation: Postman, Insomnia, and Thunder Client. Each takes a different stance on how much power, complexity, and cost an API workflow should carry.

This comparison looks at where each tool stands in 2024, based on current features, pricing, and the kinds of teams that tend to adopt them. There is no single winner — only a best fit for how you work.

The Contenders at a Glance

Postman launched in 2012 as a Chrome extension and grew into a full API platform: design, testing, mocking, documentation, monitoring, and collaboration. It is the default choice in most enterprise environments.

Insomnia, acquired by Kong in 2019, started as a lean REST and GraphQL client and has expanded into design and testing while keeping a cleaner interface than Postman’s.

Thunder Client arrived in 2020 as a Visual Studio Code extension. It is lightweight, fast, and lives inside the editor — no separate app, no account required for basic use.

Feature Depth

Postman is the most feature-complete of the three. Beyond sending requests, it offers:

• Collection Runner for automated test suites
• Mock servers that simulate endpoints before the backend exists
• API documentation generated from collections and published as web pages
• Monitors that run collections on a schedule and alert on failures
• Flows, a low-code visual builder for chaining requests
• CLI (Newman) for CI/CD pipelines

Insomnia covers the core well: REST, GraphQL, gRPC, WebSocket, environment variables, code generation, and a plugin ecosystem. Its design and test suites (introduced after the Kong acquisition) add spec editing and unit testing, though they remain less mature than Postman’s equivalents.

Thunder Client focuses on the essentials: HTTP requests, collections, environments, and basic testing. It added a CLI and Git sync in recent versions, but it does not attempt to be a full API lifecycle platform. For quick endpoint checks during development, that restraint is the point.

Performance and Resource Use

Thunder Client wins on footprint by a wide margin. It runs inside VS Code, so there is no second application consuming memory. Developers on older laptops or with many browser tabs open tend to notice this immediately.

Postman is an Electron app and, with large collections, can consume several hundred megabytes of RAM. Insomnia is also Electron-based but generally feels lighter than Postman in day-to-day use, particularly with GraphQL queries.

If you spend most of your day in VS Code and only need to fire off requests between edits, Thunder Client’s zero-context-switch workflow is hard to beat.

Collaboration and Team Features

This is where Postman pulls ahead. Workspaces, role-based access, shared environments, comment threads on requests, and version history make it viable for teams of dozens or hundreds. API governance features — style guides, security linting, and audit trails — target organizations that treat APIs as products.

Insomnia supports team collaboration through Kong’s cloud sync, including shared collections and environments. It is adequate for small to mid-sized teams but lacks the administrative depth of Postman’s enterprise tier.

Thunder Client’s collaboration story is the thinnest. Teams can sync collections through Git or a paid Teams plan, but it was built for individual developers first.

Pricing in 2024

• Postman: Free tier for individuals with limits on collection runs and monitoring. Basic starts around $14 per user per month (annual billing), Professional around $29, and Enterprise pricing is custom. Prices have shifted over time, so check the current page.
• Insomnia: Free tier with local storage. Individual paid plans start around $12 per month (annual), Team plans around $24 per user per month, and Enterprise is custom.
• Thunder Client: Free for individual use. The paid plan is roughly $5 per user per month (annual), covering team sharing and unlimited collections.

For solo developers, all three have usable free tiers. The gap widens sharply at team scale, where Postman’s per-seat cost becomes a real budget line.

Developer Experience

Postman’s interface has grown dense over the years. New users often describe it as overwhelming, and finding a specific setting can take longer than expected. The upside is that almost anything you need exists somewhere.

Insomnia’s UI is cleaner and more focused. Keyboard-driven workflows feel faster, and the request builder stays out of the way. Some developers find its plugin ecosystem less active than Postman’s.

Thunder Client is the simplest of the three. The learning curve is measured in minutes, and the VS Code integration means your request history sits next to your code. The trade-off is fewer advanced features and a smaller community for troubleshooting.

Which Should You Choose?

Choose Postman if you work on a large team, need API documentation, mocking, monitoring, or CI/CD integration, and your organization is willing to pay for governance and collaboration.

Choose Insomnia if you want a polished client for REST and GraphQL work, value a clean interface, and need moderate team features without Postman’s complexity or price.

Choose Thunder Client if you live in VS Code, mostly test endpoints during development, and want something fast and free without leaving your editor.

Many developers use more than one. A common pattern is Thunder Client for quick checks while coding and Postman or Insomnia for deeper testing and team-shared collections. Nothing requires you to commit to a single tool.

The Takeaway

There is no objectively best API client in 2024 — only a best match for your workflow, team size, and budget. Postman offers the deepest platform, Insomnia balances power and usability, and Thunder Client trades features for speed and simplicity. Start with the free tier of the one that fits your daily habits, and switch when it stops fitting. The cost of trying all three is a few hours; the cost of forcing the wrong one on a team is considerably higher.