How to manually send HTTP POST requests from Firefox or Chrome browser?

CURL is awesome to do what you want! It's a simple, but effective, command line tool.

REST implementation test commands:

curl -i -X GET http://rest-api.io/items
curl -i -X GET http://rest-api.io/items/5069b47aa892630aae059584
curl -i -X DELETE http://rest-api.io/items/5069b47aa892630aae059584
curl -i -X POST -H 'Content-Type: application/json' -d '{"name": "New item", "year": "2009"}' http://rest-api.io/items
curl -i -X PUT -H 'Content-Type: application/json' -d '{"name": "Updated item", "year": "2010"}' http://rest-api.io/items/5069b47aa892630aae059584

Firefox

Open Network panel in Developer Tools by pressing Ctrl+Shift+E or by going Menubar -> Tools -> Web Developer -> Network. Then Click on small door icon on top-right (in expanded form in the screenshot, you'll find it just left of the highlighted Headers), second row (if you don't see it then reload the page) -> Edit and resend whatever request you want

I have been making a Chrome app called Postman for this type of stuff. All the other extensions seemed a bit dated so made my own. It also has a bunch of other features which have been helpful for documenting our own API here.

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Postman now also has native apps (i.e. standalone) for Windows, Mac and Linux! It is more preferable now to use native apps, read more here.

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