Downloading Images from Chrome Network via HAR

1. Enable HAR export with sensitive data

   • Open Chrome DevTools with F12.
   • Press F1 to open DevTools Settings.
   • Under Network, enable Allow to generate HAR with sensitive data.
   • This is necessary because the image requests may depend on your login/session cookies.

2. Load all images in Network

   • Open DevTools → Network.
   • Clear the existing requests if necessary.
   • Reload the webpage.
   • Scroll through/open the page until all images have loaded.
   • If useful, filter the Network list for the image endpoint, for example: docImage.action
   • Click a few requests and check Preview to confirm they contain the correct images.

3. Export the requests as HAR

   • In the Network request list, right-click.
   • Choose the HAR export option that includes sensitive data.
   • Save the file, for example as: images.har

   Important: The sensitive HAR may contain login/session cookies. Do not share it with other people.

4. Prepare the PowerShell script

   • Put images.har and the .ps1 download script in the same folder.

   • Make sure the script refers to the correct HAR filename, for example:

     $har = Get-Content ".\images.har" -Raw | ConvertFrom-Json
     

5. Open PowerShell in that folder

   • In Windows Explorer, open the folder containing the HAR and script.
   • Right-click inside the folder and choose Open in Terminal, or navigate to the folder in PowerShell.

6. Allow scripts for this PowerShell session only Run:

   Set-ExecutionPolicy -Scope Process -ExecutionPolicy Bypass
   

   This permission lasts only until you close that PowerShell window.

7. Run the script If the script is called download-images.ps1, run:

   .\download-images.ps1
   

8. Check the downloaded images

   • The script creates an output folder, such as: images
   • The files should appear as: image_0001.jpg image_0002.jpg image_0003.jpg etc.

The key point is that the HAR with sensitive data preserves the session information Chrome uses to access the images. Without it, requesting the .action URLs separately may return an HTML login/error page instead of the actual image.

DO NOT FORGET TO REVERSE (TURN OFF HAR SENSETIVE) FROM THE STEP 1

download-images.ps1 content be like

# get the har content
$har = Get-Content ".\images.har" -Raw | ConvertFrom-Json

# set the out directory
$out = ".\images"
New-Item -ItemType Directory -Force $out | Out-Null

$session = New-Object Microsoft.PowerShell.Commands.WebRequestSession

# Import cookies from HAR
foreach ($entry in $har.log.entries) {
    try {
        $uri = [Uri]$entry.request.url

        foreach ($c in $entry.request.cookies) {
            $cookie = New-Object System.Net.Cookie
            $cookie.Name  = $c.name
            $cookie.Value = $c.value
            $cookie.Domain = $uri.Host
            $cookie.Path = "/"

            $session.Cookies.Add($uri, $cookie)
        }
    } catch {}
}

$i = 1

# run through entries and download one by one : jpg eg, png, web (add what you want in if elseif)
foreach ($entry in $har.log.entries) {

    $url = [string]$entry.request.url

    if ($url -notmatch 'docImage\.action') {
        continue
    }

    $headers = @{}

    foreach ($h in $entry.request.headers) {
        $name = [string]$h.name

        if ($name -notmatch '^(Cookie|Host|Content-Length|Connection)$') {
            $headers[$name] = [string]$h.value
        }
    }

    try {
        $r = Invoke-WebRequest `
            -Uri $url `
            -Headers $headers `
            -WebSession $session `
            -Method GET

        $type = [string]$r.Headers["Content-Type"]

        if ($type -match 'image/jpeg') {
            $ext = ".jpg"
        }
        elseif ($type -match 'image/png') {
            $ext = ".png"
        }
        elseif ($type -match 'image/webp') {
            $ext = ".webp"
        }
        else {
            Write-Host "NOT IMAGE: $type | $url"
            continue
        }

        $file = Join-Path $out ("image_{0:D4}{1}" -f $i, $ext)

        [IO.File]::WriteAllBytes(
            $file,
            $r.Content
        )

        Write-Host "Saved image_$('{0:D4}' -f $i)$ext"
        $i++
    }
    catch {
        Write-Host "FAILED: $url"
    }
}

Write-Host ""
Write-Host "Saved:" ($i - 1)