Next.js / payslips
Payslip PDFs in Next.js
Post your payslip HTML to a render API from a Route Handler returning a Response, then return a Response with the upstream body and a PDF content type. No browser binary in your Next.js deployment.
Why payslips become PDFs
A payslip is a personal financial record an employee keeps, uses to apply for credit, and expects to be able to open years later. That is the difference between a document and a view of a database, and it is why HR and payroll teams keep asking for this.
What a payslip has to carry
Before any of the code below matters, the template has to produce a document that is actually a payslip. These are the fields that make it one, and the ones a reader or an auditor will look for first.
- gross pay, itemised by basic, overtime and any allowances
- each deduction named separately with its own amount
- net pay, which is the number the employee checks first
- year-to-date totals for gross, tax and net
- the pay period and the payment date, which are not the same day
- the employee identifier and tax reference
Turning your React, rendered to a string on the server template into a document
You already have the markup. RenderToStaticMarkup(<Invoice {...data} />) gives you it as a string, which is the only input the render needs. This is the framework where the incumbent approach fails hardest. A serverless function has a hard bundle size limit, and a Chromium build does not fit inside it. That is why the ecosystem grew a whole genre of stripped Chromium packages, and why an HTTP render is the path of least resistance here rather than an optimisation.
The Next.js implementation
fetch ships with the runtime, so this adds no dependency. The render happens in a Route Handler returning a Response, and you return a Response with the upstream body and a PDF content type.
// app/payslips/[id]/pdf/route.ts
import { renderToStaticMarkup } from "react-dom/server";
import { PayslipDocument } from "@/documents/payslip";
import { documentStyles } from "@/documents/styles";
export async function GET(
_request: Request,
{ params }: { params: Promise<{ id: string }> },
) {
const { id } = await params;
const payslip = await getPayslip(id);
// The style tag is the load-bearing part. Your app's CSS lives in a bundle the
// renderer will never fetch, so the document needs its styles inline.
const html = `<!doctype html><html><head><meta charset="utf-8">
<style>${documentStyles}</style></head><body>${renderToStaticMarkup(
<PayslipDocument payslip={payslip} />,
)}</body></html>`;
const upstream = await fetch("https://api.pdfpipe.xyz/v1/pdf", {
method: "POST",
headers: {
Authorization: `Bearer ${process.env.PDFPIPE_KEY}`,
"Content-Type": "application/json",
},
body: JSON.stringify({
html,
options: { format: "A4", printBackground: true },
}),
});
if (!upstream.ok) {
return new Response("render failed", { status: 502 });
}
return new Response(upstream.body, {
headers: {
"Content-Type": "application/pdf",
"Content-Disposition": `attachment; filename="payslip-${id}.pdf"`,
},
});
}The CSS that makes a payslip page correctly
The layout problem specific to this document is that gross, deductions and net must be visible together without scrolling or breaking, on one page, every time. These rules handle it.
/* Gross, deductions and net have to be visible together. One page,
every time, regardless of how many deduction lines there are. */
.payslip { break-inside: avoid; }
.summary { break-inside: avoid; }
@page { size: A4; margin: 15mm; }What goes wrong in Next.js
renderToStaticMarkup gives you markup with no stylesheet attached, because your CSS lives in a bundle the PDF renderer will never load. Inline the styles into a style tag in the string you send, or the document renders with browser defaults.
What people try first
Most Next.js projects reach for puppeteer-core paired with a size-reduced Chromium package, which works but ties your deployment to a binary that has to be rebuilt for every runtime version bump. That works until it is running on more than one machine, at which point the browser becomes the thing you operate rather than the thing you use.
Where the payslip lives afterwards
Rendering is the short part. Payslips are personal financial records the employee will need for credit applications and tax filings for years. Employers commonly retain them for six years, and employees expect to be able to download an old one long after they have left.
Getting the document right
- Check net pay and the deduction breakdown, which is what an employee checks first and complains about immediately.
- Generation is triggered by a payroll run, producing every employee's document at once, so size the timeout for that path rather than for a health check.
- This is a batch shape: render the run through the batch endpoint rather than firing thousands of individual requests.
- Backgrounds are painted by default here, so a design that uses colour needs nothing set. Only an explicit print_background of false turns them off.
Frequently asked
Do I need Chromium installed to generate payslips from Next.js?
No. The render happens over HTTP, so your Next.js deployment stays the size it is now. That is the main reason to use an API rather than puppeteer-core paired with a size-reduced Chromium package, which works but ties your deployment to a binary that has to be rebuilt for every runtime version bump.
How do I stop a long payslip using all the memory?
Return a Response with the upstream body and a PDF content type. renderToStaticMarkup gives you markup with no stylesheet attached, because your CSS lives in a bundle the PDF renderer will never load. Inline the styles into a style tag in the string you send, or the document renders with browser defaults.
What has to be on a payslip?
At minimum: gross pay, itemised by basic, overtime and any allowances; each deduction named separately with its own amount; net pay, which is the number the employee checks first. The one to get right before anything else is net pay and the deduction breakdown, which is what an employee checks first and complains about immediately.
Do I need to store the generated payslips?
Depends on the document, and this one has a clear answer: payslips are personal financial records the employee will need for credit applications and tax filings for years. Employers commonly retain them for six years, and employees expect to be able to download an old one long after they have left.
Can I keep my existing payslip template?
Yes, if it produces HTML. Whatever renders your payslip view today can render the same markup for the PDF, which is why the CSS above is the only new thing you write.
Related
Other Next.js documents, and the same payslip in other stacks.
Invoice PDFs in Next.js
an invoice is a legal record of a demand for payment
Receipt PDFs in Next.js
a receipt is proof a payment happened
Report PDFs in Next.js
a report is a snapshot of numbers at a moment in time. Its whole value is that it does not change when the underlying dashboard does.
Payslip PDFs in Node.js
Using fetch, in a route handler that returns the response body directly.
Payslip PDFs in Python
Using httpx, in an async endpoint that returns a streaming response.
Payslip PDFs in PHP
Using cURL, in a controller action that echoes the body with a PDF Content-Type.
The same thing in plain Node.js
Without the framework, using fetch directly.
When the output is wrong
Blank pages, missing backgrounds, breaks in the wrong place, by symptom.
All stacks and documents
The full grid of what this covers.
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