What is the difference between Insomnia and Thunder Client?

Insomnia is best for Developers wanting a lightweight REST and GraphQL client, while Thunder Client is best for VS Code users wanting a lightweight API client. Insomnia starts at Free and Thunder Client starts at Free.

Is Insomnia or Thunder Client cheaper?

Insomnia starts at Free with a free tier. Thunder Client starts at Free and is free.

Is there a free alternative to Thunder Client?

Both Insomnia and Thunder Client offer free tiers.

Insomnia vs Thunder Client

Insomnia is Open-source API client for REST, GraphQL, and gRPC with environment variables and plugin support, while Thunder Client is Lightweight REST API client built into VS Code with collections and environments. Insomnia is open source and can be self-hosted, giving you full control over your data. Insomnia is built for developers wanting a lightweight rest and graphql client, whereas Thunder Client targets vs code users wanting a lightweight api client.

At a glance

	Insomnia	Thunder Client
Best for	Developers wanting a lightweight REST and GraphQL client	VS Code users wanting a lightweight API client
Starting price	Free	Free
Free tier	✓	✓
Open source	✓	—
Free tier available	✓	✓
Open source	✓	—
CLI	—	✓
Collections	—	✓
Git Sync	—	✓
GraphQL	✓	—
Plugins	✓	—
REST	✓	—
VS Code Extension	—	✓
gRPC	✓	—

Insomnia

Strengths

Open source and transparent
Includes REST as a core feature, purpose-built for api development workflows
Fully open-source — you can self-host, audit the code, and avoid vendor lock-in
Free for individuals — generous enough for most small teams to get real work done

Weaknesses

Free plan exists but key features are locked behind the paid upgrade
Fewer built-in features means you may need additional tools to cover gaps
Ecosystem of third-party integrations is smaller than the market leaders in api development
Community support can be slower than the dedicated support teams at commercial alternatives

Try Insomnia → Full review

Thunder Client

Strengths

Includes VS Code Extension as a core feature, purpose-built for api development workflows
Includes Collections as a core feature, purpose-built for api development workflows
The core product is free with no paywalled essentials
Includes cli alongside the core feature set — fewer separate tools needed

Weaknesses

May lack some advanced features
Some advanced features require upgrading to a paid plan
Fewer built-in features means you may need additional tools to cover gaps
Ecosystem of third-party integrations is smaller than the market leaders in api development

Try Thunder Client → Full review

The bottom line

Pricing: Both Insomnia and Thunder Client are free. You can try both without spending a dollar.

Feature gaps: Insomnia offers GraphQL, Plugins and REST that Thunder Client lacks. Thunder Client brings CLI, Collections and Git Sync that Insomnia does not have.

Team fit: Both tools target individuals teams, so the decision hinges on features and workflow fit rather than scale.

Open source: Insomnia is open source, meaning you can self-host, audit the code, and avoid vendor lock-in. Thunder Client is proprietary — you are trusting the vendor with your data and uptime.

Where each tool shines: Insomnia's biggest strengths are: open source and transparent. includes rest as a core feature, purpose-built for api development workflows. Thunder Client's biggest strengths are: includes vs code extension as a core feature, purpose-built for api development workflows. includes collections as a core feature, purpose-built for api development workflows.

Watch out for: With Insomnia, users commonly note that free plan exists but key features are locked behind the paid upgrade. With Thunder Client, the main complaint is that may lack some advanced features.

Choose Insomnia if...

Your profile matches its sweet spot: developers wanting a lightweight rest and graphql client
You need self-hosting, data sovereignty, or the ability to audit source code
You specifically need GraphQL and Plugins
You care about includes rest as a core feature, purpose-built for api development workflows
The free tier works for you: free for individuals

Choose Thunder Client if...

You need a tool built for vs code users wanting a lightweight api client
You specifically need CLI and Collections
You care about includes collections as a core feature, purpose-built for api development workflows