Windows API testing tool for developers and QA

Forge better API test cases from JSON payloads.

Payload Forge helps you validate JSON, detect fields, configure payload values, add custom headers and authorization, create reusable expected cases, and run API tests from one focused Windows desktop app.

Buy Payload Forge See Features

One-time download. Built for REST APIs, JSON payload testing, and fast validation workflows.

Everything you need for focused API payload testing.

Payload Forge is built around the repetitive testing developers actually do: changing JSON values, checking expected status codes, and confirming response text.

{ }

JSON validation and field detection

Paste a JSON payload and automatically detect editable fields including strings, numbers, booleans, dates, emails, UUIDs, and null values.

⚙

Configurable payload generation

Set field behavior such as fixed values, generated emails, random names, random numbers, current dates, UUIDs, one-of values, and nulls.

✓

Reusable expected cases

Create named cases with expected HTTP status codes and expected response text so validation scenarios can be repeated quickly.

↯

Per-case field overrides

Override a specific field for each case. Test blank values, null values, invalid types, edge cases, and custom inputs without rebuilding your payload.

🔐

Headers and authorization

Add custom headers and configure authorization for APIs that require bearer tokens, JWTs, API keys, basic auth, or custom auth headers.

💾

Save and load projects

Save the URL, method, JSON, field settings, expected cases, overrides, headers, and authorization settings into a reusable project file.

A faster workflow for API validation.

Stop recreating the same negative test cases by hand. Build once, run repeatedly, and save the project for later.

Paste JSON

Start with the request payload your endpoint expects.

Detect fields

Payload Forge extracts editable paths from the payload.

Add cases

Create scenarios like missing username, invalid email, or null password.

Run tests

Send requests, check expected results, and review responses.

Buy once. Use it on your Windows machine.

Payload Forge is a focused desktop utility for developers who need repeatable API request testing without heavy setup.

  • Windows desktop application
  • JSON payload field detection
  • Reusable test case projects
  • Custom headers and authorization
  • Useful for backend development and QA workflows
Payload Forge License
$19

Replace this price if your Lemon Squeezy product uses a different amount.

Buy Now

Secure checkout powered by Lemon Squeezy. Replace the button URL with your checkout link.

Frequently asked questions

Simple answers for developers and QA users evaluating Payload Forge.

Is Payload Forge a replacement for Postman?

No. Payload Forge is more focused. It is designed for quickly generating payload variations, expected cases, overrides, and repeatable JSON API tests.

Does it support authenticated APIs?

Yes. You can add custom headers and configure authorization values for APIs that require bearer tokens, JWTs, API keys, basic auth, or custom headers.

Can I save my work?

Yes. Projects can store your URL, HTTP method, JSON payload, field settings, expected cases, overrides, headers, and authorization settings.

Who is this for?

Payload Forge is built for backend developers, QA testers, indie developers, and anyone validating REST APIs with JSON request bodies.