---
title: Apply Watermark to PDF File API
slug: apply-watermark-to-pdf-file
url: https://apyhub.com/freedailypro/service/apply-watermark-to-pdf-file
provider: FreeDailyPro
tags: [watermark, text, pdf, apply, file]
auth: api_key
version: v1
service_type: sync
endpoints: 1
atoms: 10
mcp: true
---

# Apply Watermark to PDF File API

Easily apply text watermarks to PDF files using the Apply Watermark to PDF File API. Customize opacity, font size, position, and rotation.

## Endpoints

| Method | URL | Description | Atoms |
| --- | --- | --- | --- |
| POST | `https://api.eu.apyhub.com/freedailypro/apply-watermark-to-pdf-file/watermark` | What it does Adds a text watermark to a PDF by taking an uploaded PDF file and watermark text, then… | 10 |

## Endpoint reference

### Add a text watermark to a PDF

`POST https://api.eu.apyhub.com/freedailypro/apply-watermark-to-pdf-file/watermark` · 10 atoms · accepts `multipart/form-data` · returns `application/json`

| Parameter | In | Type | Required | Description |
| --- | --- | --- | --- | --- |
| `file` | body | string (binary) | yes | The PDF. Up to 20 MB. |
| `text` | body | string | yes | Watermark text |
| `opacity` | body | number | no | 0 to 1 |
| `fontSize` | body | number | no | Font size in points |
| `position` | body | string | no | Position, for example center |
| `rotationDegrees` | body | number | no | Rotation in degrees |

#### Quickstart

Upload a PDF and add watermark text to generate a watermarked file.

```bash
curl -X POST "https://api.eu.apyhub.com/freedailypro/apply-watermark-to-pdf-file/watermark" \
  -H "apy-token: $APY_TOKEN" \
  -F "file=@/path/to/file.pdf" \
  -F "text=Confidential"
```

#### What you'll get back

Returns a binary file (`string` with `format: binary`) — the watermarked PDF.

```bash
<binary file>
```

## About

## What it does
PDF Watermark adds a text watermark to a PDF and returns the modified file as binary output. Send a PDF plus the watermark text, and you can control how it appears with optional opacity, font size, position, and rotation.

Use it when you need to mark internal documents, label draft versions, or stamp files before sharing them with customers or partners. The input is a single PDF file up to 20 MB, along with the text you want placed on the page.

The response is the watermarked PDF file itself, so it fits cleanly into document workflows where you need to store, download, or forward the updated file without extra parsing. If you are building a document pipeline, PDF Watermark gives you a simple way to add consistent branding or status labels to outgoing PDFs.

## Usage

Base URL: `https://api.eu.apyhub.com` (default region — see
`GET https://apyhub.com/api/public/regions` for the rest).

Authenticate with an ApyHub API key in the `apy-token` header.
Full docs and a live playground: https://apyhub.com/freedailypro/service/apply-watermark-to-pdf-file