PDF Tools API

Merge PDFs, extract or split pages, rotate pages, stamp a diagonal watermark or add page numbers (Vietnamese text supported), all in one API.

POSThttps://apibox.io.vn/v1/pdf-tools

Files▶ Try it online

One endpoint, several actions. merge joins up to 20 PDFs in order (multipart file1, file2… or a files_base64 array). extract builds a new PDF from pages such as 1-3,5,8-last (in the order given, so 3,1 reorders). split cuts the document every N pages (every) or by ranges (ranges=1-3;4-6) and returns a ZIP of the parts. rotate turns pages by 90, 180 or 270 degrees. info (the default) returns the page count, title, producer and page size.

watermark draws a semi-transparent diagonal text (text, opacity 0.03–1, default 0.15) across each page, sized to the page; page_numbers writes labels such as Trang {n}/{total} (format, position top / bottom + left / center / right, start). Both use the Be Vietnam Pro font, so “BẢN NHÁP” or “Trang 1/5” render with correct diacritics. Every action except merge accepts pages to work on part of the document.

The answer is the resulting PDF (or ZIP for split, JSON for info). Password-protected PDFs are refused; files are processed in memory within the file size of your plan.

Parameters

Name	In	Type	Required	Default
`action`	query\|body	string	no	`info`	`merge`, `extract`, `split`, `rotate`, `watermark`, `page_numbers` or `info`.
`file`	body	file	yes		The PDF (multipart, raw body or `file_base64`). For `merge`: `file1`, `file2`… (up to `file10`) or `files_base64` (array, up to 20).
`pages`	query\|body	string	no		Pages, e.g. `1-3,5,8-last`. Required for `extract`; for rotate / watermark / page_numbers it limits the pages (default: all).
`every`	query\|body	number	no	`1`	`split`: pages per part.
`ranges`	query\|body	string	no		`split`: explicit parts separated by `;`, e.g. `1-3;4-6` (max 200 parts).
`angle`	query\|body	number	no	`90`	`rotate`: 90, 180 or 270 (-90 also accepted).
`text`	query\|body	string	no		`watermark`: the text (required, max 100 characters).
`opacity`	query\|body	number	no	`0.15`	`watermark`: 0.03–1.
`format`	query\|body	string	no	`{n} / {total}`	`page_numbers`: label with `{n}` and `{total}`.
`position`	query\|body	string	no	`bottom-center`	`page_numbers`: `top-` or `bottom-` + `left`, `center`, `right`.
`start`	query\|body	number	no	`1`	`page_numbers`: first number.

Example

curl -X POST "https://apibox.io.vn/v1/pdf-tools" \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -F "0=@./my-file"

const form = new FormData();
form.append('0', fileInput.files[0]);

const res = await fetch('https://apibox.io.vn/v1/pdf-tools', {
  method: 'POST',
  headers: { Authorization: 'Bearer YOUR_API_KEY' },
  body: form,
});
console.log(await res.json());

import requests

res = requests.post(
    "https://apibox.io.vn/v1/pdf-tools",
    headers={"Authorization": "Bearer YOUR_API_KEY"},
    files={"0": open("my-file", "rb")},
    timeout=30,
)
print(res.json())

<?php
$ch = curl_init('https://apibox.io.vn/v1/pdf-tools');
curl_setopt_array($ch, [
    CURLOPT_RETURNTRANSFER => true,
    CURLOPT_CUSTOMREQUEST => 'POST',
    CURLOPT_HTTPHEADER => ['Authorization: Bearer YOUR_API_KEY'],
    CURLOPT_POSTFIELDS => ['0' => new CURLFile('my-file')],
]);
$response = curl_exec($ch);
print_r(json_decode($response, true));

Response

{
  "pages": 1,
  "title": "Báo giá",
  "author": null,
  "producer": "APIBox md-pdf",
  "page_size_pt": {
    "width": 595,
    "height": 842
  },
  "actions": [
    "merge",
    "extract",
    "split",
    "rotate",
    "watermark",
    "page_numbers",
    "info"
  ]
}

Use cases

Merge an invoice and its appendix into one PDF
Stamp “BẢN NHÁP” or “CONFIDENTIAL” on drafts
Add page numbers to generated reports
Split a scanned bundle into one PDF per document

FAQ

How do I select pages?

pages=1-3,5,8-last; ranges can go backwards (5-1) and pages are taken in the order written.

Can it open password-protected PDFs?

No. Remove the password first; the API answers invalid_pdf otherwise.

Does it compress PDFs?

No, the pages are copied as they are. Use it to merge, split and mark documents.

Related APIs

EXIF

PDF Tools API

Parameters

Example

Response

Use cases

FAQ

Related APIs

Image Metadata & EXIF

PDF Metadata

Quote & Receipt PDF