WarmySender for LinkedIn: run LinkedIn from your browser

Install in five steps

1. Download and unzip. Unzip it somewhere you will keep, for example Documents. You get a folder called WarmySender-LinkedIn-Extension. The browser loads the extension from this folder, so do not delete or move it afterwards.
2. Turn on Developer mode. Open your browser's extensions page and switch on Developer mode. Where both are, browser by browser, is listed below.
3. Load unpacked. Click Load unpacked and choose the WarmySender-LinkedIn-Extension folder (the one with manifest.json directly inside).
4. Sign in to LinkedIn in a tab, with the account you want campaigns to run from, and keep that tab open while campaigns run.
5. Connect it in WarmySender. Go to LinkedIn → Accounts → Connect → Run from your browser. The extension pairs itself while the connect dialog is on screen; there is nothing to type.

Full walkthrough: LinkedIn from your browser: the free extension.

Your browser, step by step

Works in Chrome, Edge, Brave, Arc, Opera and Vivaldi. Firefox and Safari aren't supported yet. To run LinkedIn without one of these browsers, use a Cloud seat. See plans.

Chrome

• Extensions page: Paste chrome://extensions into the address bar and press Enter.
• Developer mode: The switch is in the top-right corner of the Extensions page.
• Button to click: Load unpacked
• After an update: press the circular reload arrow on the WarmySender card.
• Start-up notice: At start-up the browser may ask whether to "Disable developer mode extensions". Choose Cancel. Disable would switch the WarmySender extension off.

Edge

• Extensions page: Paste edge://extensions into the address bar and press Enter, or open the ⋯ menu → Extensions → Manage extensions.
• Developer mode: The switch is on the left-hand side of the Extensions page.
• Button to click: Load unpacked
• After an update: press the Reload link on the WarmySender card.
• Start-up notice: Edge shows a notice about extensions in developer mode, and Microsoft doesn't allow that notice to be switched off. You can ignore it: the extension keeps working as long as you don't choose to turn developer-mode extensions off.

Brave

• Extensions page: Paste brave://extensions into the address bar and press Enter.
• Developer mode: The switch is in the top-right corner of the Extensions page.
• Button to click: Load unpacked
• After an update: press the circular reload arrow on the WarmySender card.
• Start-up notice: At start-up the browser may ask whether to "Disable developer mode extensions". Choose Cancel. Disable would switch the WarmySender extension off.

Arc

• Extensions page: Press ⌘T (Mac) or Ctrl+T (Windows), type Manage Extensions and press Enter.
• Developer mode: The switch is in the top-right corner of the Extensions page.
• Button to click: Load unpacked
• After an update: press the circular reload arrow on the WarmySender card.
• Start-up notice: At start-up the browser may ask whether to "Disable developer mode extensions". Choose Cancel. Disable would switch the WarmySender extension off.
• Note: Arc's maker is retiring Arc on December 22, 2026. After that date, install the extension in another browser on this list.

Opera

• Extensions page: Paste opera:extensions into the address bar and press Enter, or press Ctrl+Shift+E (⌘⇧E on Mac).
• Developer mode: Look for it by name on the Extensions page.
• Button to click: Load unpacked (some versions say Load unpacked extension)
• After an update: press the reload button on the WarmySender card.
• Start-up notice: At start-up the browser may ask whether to "Disable developer mode extensions". Choose Cancel. Disable would switch the WarmySender extension off.

Vivaldi

• Extensions page: Paste vivaldi://extensions into the address bar and press Enter, or press Ctrl+Shift+E (⌃⌘E on Mac).
• Developer mode: The switch is in the top-right corner of the Extensions page.
• Button to click: Load unpacked
• After an update: press the circular reload arrow on the WarmySender card.
• Start-up notice: At start-up the browser may ask whether to "Disable developer mode extensions". Choose Cancel. Disable would switch the WarmySender extension off.

Which plans include the LinkedIn browser extension?

It is free with your plan: Pro includes 1 LinkedIn account, Enterprise 4 and Ultimate 10. A trial includes the allowance of the plan you are trying. AppSumo lifetime plans do not include it; LinkedIn on those plans is the Cloud seat add-on.

Is it as safe as a Cloud seat?

It follows the same safe daily limits, gradual warm-up, pacing and working hours as every WarmySender LinkedIn account. Those limits are decided on our side; the extension only performs the actions your campaign has scheduled, one at a time, with natural pauses.

It never stores your LinkedIn password and never reads other websites.

What happens when my browser is closed?

The campaign waits. Nothing is lost, nobody is skipped, and the campaign continues from the next person when the browser is open and you are signed in to LinkedIn again. To keep LinkedIn running with your laptop closed, use a Cloud seat.

Which browsers does it work in?

Chrome, Edge, Brave, Arc, Opera and Vivaldi. Firefox and Safari aren't supported yet. To run LinkedIn without one of these browsers, use a Cloud seat.

About the "developer mode" notice

Because the extension is installed from a folder rather than a store, your browser reminds you about it. What each browser shows and what to click is listed above. In short, keep the extension on and never choose the option that turns developer-mode extensions off.

Update

Folder-installed extensions do not update themselves. When a new version is ready, this page and the extension tell you.

1. Download the new zip and unzip it.
2. Replace everything inside your WarmySender-LinkedIn-Extension folder with the new files.
3. On your browser's extensions page, press reload on the WarmySender card.

Remove

1. On your browser's extensions page, click Remove on the WarmySender card.
2. In WarmySender, open LinkedIn → Accounts, click ⋮ on that account and choose Remove account.

Troubleshooting

• The extension's card shows errors: download the zip again, replace the folder's contents, and press reload on the card.
• "Extension detected" never ticks: reload the WarmySender tab after loading the extension.
• Keep a LinkedIn tab open and signed in. Campaigns wait while LinkedIn is signed out.
• One browser profile per LinkedIn account.
• If the Developer mode switch is greyed out or Load unpacked is missing, your browser is managed by a workplace or school and folder-installed extensions are blocked. Use a personal browser profile, or a Cloud seat.

Where to go next

• LinkedIn from your browser — the full guide
• Browser extension or Cloud seat — which one?
• Multichannel outreach — email and LinkedIn in one sequence (Cloud seat)
• Pricing — plans and the Cloud seat add-on