What is the difference between Stoplight and Thunder Client?

Stoplight is best for API teams wanting design-first API development, while Thunder Client is best for VS Code users wanting a lightweight API client. Stoplight starts at Free and Thunder Client starts at Free.

Is Stoplight or Thunder Client cheaper?

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

Is there a free alternative to Thunder Client?

Both Stoplight and Thunder Client offer free tiers.

Stoplight vs Thunder Client

Stoplight is API design, documentation, and governance platform with OpenAPI support, while Thunder Client is Lightweight REST API client built into VS Code with collections and environments. Stoplight is built for api teams wanting design-first api development, whereas Thunder Client targets vs code users wanting a lightweight api client.

At a glance

	Stoplight	Thunder Client
Best for	API teams wanting design-first API development	VS Code users wanting a lightweight API client
Starting price	Free	Free
Free tier	✓	✓
Open source	—	—
Free tier available	✓	✓
Open source	—	—
API Design	✓	—
CLI	—	✓
Collections	—	✓
Docs	✓	—
Git Sync	—	✓
Mock Servers	✓	—
Style Guides	✓	—
VS Code Extension	—	✓

Stoplight

Strengths

Includes API Design as a core feature, purpose-built for api development workflows
Includes Mock Servers as a core feature, purpose-built for api development workflows
Free for 1 project — generous enough for most small teams to get real work done
Established product with 11+ years on the market and a mature ecosystem

Weaknesses

Free plan exists but key features are locked behind the paid upgrade
Developer-oriented tooling may not suit non-technical team members
Ecosystem of third-party integrations is smaller than the market leaders in api development
Mobile experience lags behind the desktop version in features and polish

Try Stoplight → 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 Stoplight and Thunder Client are free. You can try both without spending a dollar.

Feature gaps: Stoplight offers API Design, Docs and Mock Servers that Thunder Client lacks. Thunder Client brings CLI, Collections and Git Sync that Stoplight does not have.

Team fit: Stoplight is geared toward mid-size teams teams, while Thunder Client is aimed at individual users and small setups. Pick the one that matches where your team is today and where it is headed — migrating tools later is always painful.

Where each tool shines: Stoplight's biggest strengths are: includes api design as a core feature, purpose-built for api development workflows. includes mock servers 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 Stoplight, 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 Stoplight if...

You need a tool built for api teams wanting design-first api development
You specifically need API Design and Docs
You care about includes mock servers as a core feature, purpose-built for api development workflows
Your team size fits the mid-size teams profile Stoplight is designed for
The free tier works for you: free for 1 project

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
Your team size fits the individuals profile Thunder Client is designed for