Render Authenticated Web Pages to PDF Using Cookies

Rendering invoices and statements behind login

A customer's invoice sits on a session-protected route, and your application already holds their session. Pass that session ID straight through CustomCookies:

using IronPdf;
using System.Collections.Generic;

var renderer = new ChromePdfRenderer();
renderer.RenderingOptions.RequestContext = IronPdf.Rendering.RequestContexts.Global;
renderer.RenderingOptions.CustomCookies = new Dictionary<string, string>
{
    { "ASP.NET_SessionId", sessionId }
};

renderer.RenderUrlAsPdf("https://app.example.com/account/invoices/1042")
        .SaveAs("invoice-1042.pdf");

using IronPdf;
using System.Collections.Generic;

var renderer = new ChromePdfRenderer();
renderer.RenderingOptions.RequestContext = IronPdf.Rendering.RequestContexts.Global;
renderer.RenderingOptions.CustomCookies = new Dictionary<string, string>
{
    { "ASP.NET_SessionId", sessionId }
};

renderer.RenderUrlAsPdf("https://app.example.com/account/invoices/1042")
        .SaveAs("invoice-1042.pdf");

Imports IronPdf
Imports System.Collections.Generic

Dim renderer As New ChromePdfRenderer()
renderer.RenderingOptions.RequestContext = IronPdf.Rendering.RequestContexts.Global
renderer.RenderingOptions.CustomCookies = New Dictionary(Of String, String) From {
    {"ASP.NET_SessionId", sessionId}
}

renderer.RenderUrlAsPdf("https://app.example.com/account/invoices/1042").SaveAs("invoice-1042.pdf")

For basic or Windows authentication, reach for ApplyCookies instead. It signs in at the URL with the supplied credentials and captures the resulting cookies into the global context, which the following render then reuses:

var renderer = new ChromePdfRenderer();
renderer.RenderingOptions.RequestContext = IronPdf.Rendering.RequestContexts.Global;

var credentials = new ChromeHttpLoginCredentials
{
    NetworkUsername = "svc_reports",
    NetworkPassword = "your_password"
};

string uri = "https://app.example.com/account/invoices/1042";
renderer.ApplyCookies(uri, credentials);

renderer.RenderUrlAsPdf(uri).SaveAs("invoice-1042.pdf");

var renderer = new ChromePdfRenderer();
renderer.RenderingOptions.RequestContext = IronPdf.Rendering.RequestContexts.Global;

var credentials = new ChromeHttpLoginCredentials
{
    NetworkUsername = "svc_reports",
    NetworkPassword = "your_password"
};

string uri = "https://app.example.com/account/invoices/1042";
renderer.ApplyCookies(uri, credentials);

renderer.RenderUrlAsPdf(uri).SaveAs("invoice-1042.pdf");

Imports IronPdf

Dim renderer As New ChromePdfRenderer()
renderer.RenderingOptions.RequestContext = IronPdf.Rendering.RequestContexts.Global

Dim credentials As New ChromeHttpLoginCredentials With {
    .NetworkUsername = "svc_reports",
    .NetworkPassword = "your_password"
}

Dim uri As String = "https://app.example.com/account/invoices/1042"
renderer.ApplyCookies(uri, credentials)

renderer.RenderUrlAsPdf(uri).SaveAs("invoice-1042.pdf")

Token-based and third-party authentication

Modern apps rarely lean on simple HTTP credentials. They authenticate with JWTs, OAuth, or SAML, often storing the result in a cookie. Since CustomCookies takes any key-value pair, a bearer token or identity-provider cookie drops straight in:

renderer.RenderingOptions.CustomCookies = new Dictionary<string, string>
{
    { "auth_token", jwt },
    { "refresh_token", refreshToken }
};

renderer.RenderingOptions.CustomCookies = new Dictionary<string, string>
{
    { "auth_token", jwt },
    { "refresh_token", refreshToken }
};

Imports System.Collections.Generic

renderer.RenderingOptions.CustomCookies = New Dictionary(Of String, String) From {
    {"auth_token", jwt},
    {"refresh_token", refreshToken}
}

Personalized and localized documents

Cookies often carry locale, currency, or feature-flag state. Forward them, and the PDF matches what that specific user sees, in the correct language and currency:

renderer.RenderingOptions.CustomCookies = new Dictionary<string, string>
{
    { "locale", "en-AU" },
    { "currency", "AUD" },
    { "feature_newLayout", "on" }
};

renderer.RenderingOptions.CustomCookies = new Dictionary<string, string>
{
    { "locale", "en-AU" },
    { "currency", "AUD" },
    { "feature_newLayout", "on" }
};

renderer.RenderingOptions.CustomCookies = New Dictionary(Of String, String) From {
    {"locale", "en-AU"},
    {"currency", "AUD"},
    {"feature_newLayout", "on"}
}

Batch generation that shares one session

To generate many PDFs for the same authenticated user in sequence, set RequestContext to Global. The browser state, cookies included, persists across renders, so you authenticate once instead of per document:

var renderer = new ChromePdfRenderer();
renderer.RenderingOptions.RequestContext = IronPdf.Rendering.RequestContexts.Global;
renderer.RenderingOptions.CustomCookies = new Dictionary<string, string>
{
    { "ASP.NET_SessionId", sessionId }
};

foreach (var id in invoiceIds)
{
    renderer.RenderUrlAsPdf($"https://app.example.com/invoices/{id}")
            .SaveAs($"invoice-{id}.pdf");
}

var renderer = new ChromePdfRenderer();
renderer.RenderingOptions.RequestContext = IronPdf.Rendering.RequestContexts.Global;
renderer.RenderingOptions.CustomCookies = new Dictionary<string, string>
{
    { "ASP.NET_SessionId", sessionId }
};

foreach (var id in invoiceIds)
{
    renderer.RenderUrlAsPdf($"https://app.example.com/invoices/{id}")
            .SaveAs($"invoice-{id}.pdf");
}

Imports IronPdf.Rendering

Dim renderer As New ChromePdfRenderer()
renderer.RenderingOptions.RequestContext = RequestContexts.Global
renderer.RenderingOptions.CustomCookies = New Dictionary(Of String, String) From {
    {"ASP.NET_SessionId", sessionId}
}

For Each id In invoiceIds
    renderer.RenderUrlAsPdf($"https://app.example.com/invoices/{id}").SaveAs($"invoice-{id}.pdf")
Next

Concurrent rendering without cookie bleed

The opposite scenario carries just as much weight. A service rendering for many different users at once needs Isolated context, which gives each render a clean state and stops one user's session from leaking into another's document. Give every thread its own renderer:

using System.Threading.Tasks;

Parallel.ForEach(jobs, job =>
{
    var renderer = new ChromePdfRenderer();
    renderer.RenderingOptions.RequestContext = IronPdf.Rendering.RequestContexts.Isolated;
    renderer.RenderingOptions.CustomCookies = new Dictionary<string, string>
    {
        { "ASP.NET_SessionId", job.SessionId }
    };

    renderer.RenderUrlAsPdf(job.Url).SaveAs(job.OutputPath);
});

using System.Threading.Tasks;

Parallel.ForEach(jobs, job =>
{
    var renderer = new ChromePdfRenderer();
    renderer.RenderingOptions.RequestContext = IronPdf.Rendering.RequestContexts.Isolated;
    renderer.RenderingOptions.CustomCookies = new Dictionary<string, string>
    {
        { "ASP.NET_SessionId", job.SessionId }
    };

    renderer.RenderUrlAsPdf(job.Url).SaveAs(job.OutputPath);
});

Imports System.Threading.Tasks
Imports IronPdf.Rendering

Parallel.ForEach(jobs, Sub(job)
    Dim renderer = New ChromePdfRenderer()
    renderer.RenderingOptions.RequestContext = RequestContexts.Isolated
    renderer.RenderingOptions.CustomCookies = New Dictionary(Of String, String) From {
        {"ASP.NET_SessionId", job.SessionId}
    }

    renderer.RenderUrlAsPdf(job.Url).SaveAs(job.OutputPath)
End Sub)

Matching the method to the job

Use standard cookies (ApplyCookies) for basic HTTP auth, Windows authentication, and simple sessions. Reach for CustomCookies with tokens, multi-parameter sessions, third-party providers, and stored preferences. Pick Global to share state across renders and Isolated to keep them separate; Auto defaults to isolated and switches to global once ApplyCookies is called.

Most failures cluster around expired tokens, mismatched cookie domains, secure-cookie handling on HTTPS URLs, and SameSite policies on cross-origin requests. Confirm cookie validity before rendering, and lean on Global when sessions must persist.

When cookies are the whole job

Cookies are no edge case in PDF generation. Get them right and you ship a usable document; get them wrong and you ship a screenshot of a login form.