# Reorder the pages of a PDF

Rearrange a PDF's pages into any order you specify with page_order — pages come out exactly as listed, repeats duplicate, and omissions drop.

Rearrange the pages of a PDF into any order you specify with the
[`page_order`](#page-order) parameter. Because `page_order` uses
[ordered page syntax](/docs/api/selecting-pages), this action doubles as a
combined extract-and-reorder: pages left out are dropped and a page listed twice
is repeated. The API is stateless: your document is processed in-region and never
stored.

## Endpoint

<Endpoint method="POST" path="/v1/reorder_pages" />

Available in every region. See [Regions & data residency](/docs/api/regions-and-data-residency)
for routing and data residency.

| Region         | URL                                                 |
| -------------- | --------------------------------------------------- |
| Global         | `https://api.pdfblocks.com/v1/reorder_pages`        |
| United States  | `https://us.api.pdfblocks.com/v1/reorder_pages`     |
| US HIPAA       | `https://hipaa.api.pdfblocks.com/v1/reorder_pages`  |
| European Union | `https://eu.api.pdfblocks.com/v1/reorder_pages`     |
| United Kingdom | `https://uk.api.pdfblocks.com/v1/reorder_pages`     |
| Canada         | `https://ca.api.pdfblocks.com/v1/reorder_pages`     |
| Australia      | `https://au.api.pdfblocks.com/v1/reorder_pages`     |
| Japan          | `https://jp.api.pdfblocks.com/v1/reorder_pages`     |
| India          | `https://in.api.pdfblocks.com/v1/reorder_pages`     |
| Brazil         | `https://br.api.pdfblocks.com/v1/reorder_pages`     |

## Authentication

Authenticate every request with your secret API key in the `X-API-Key` header,
over HTTPS. Create and manage keys from the
[dashboard](https://dashboard.pdfblocks.com). See
[Authentication](/docs/api/authentication) for details.

## Request

The endpoint accepts a `multipart/form-data` request body.

<ParamField name="file" type="file" required>
  The input PDF document.
</ParamField>

<ParamField name="page_order" type="string" required>
  The desired page order, written in [the ordered page syntax](#page-order) such
  as `3,1,2`. Pages left out are dropped, and a page listed more than once is
  repeated. Maximum 1000 characters.
</ParamField>

### Page order

`page_order` is read as an **ordered list**, not a set: the pages come out
exactly as listed. A page named twice is emitted twice, and any page you leave
out is dropped. A range may even run backwards — `10..5` walks from page 10 down
to page 5.

Numbers are 1-based, and a negative index counts from the end, so `-1` is the
last page.

| `page_order` | Produces                                     |
| ------------ | -------------------------------------------- |
| `3,1,2`      | Pages 3, 1, then 2                           |
| `2..`        | Page 2 through the last page, in order       |
| `-1,1..-2`   | The last page, then every page before it     |
| `1,1,2..`    | Page 1 twice, then page 2 onward             |
| `10..5`      | Pages 10 down to 5, in reverse               |

See [Selecting pages](/docs/api/selecting-pages) for the complete reference,
including how ordered `page_order` differs from the set-based `pages` field.

## Examples

Put page 3 first, then pages 1 and 2:

<CodeGroup>

```bash title="cURL"
curl https://api.pdfblocks.com/v1/reorder_pages \
  -H 'X-API-Key: your_api_key' \
  -F file=@input.pdf \
  -F page_order='3,1,2' \
  -o reordered.pdf
```

```python title="Python"
# pip install requests
import requests

with open('input.pdf', 'rb') as file:
    response = requests.post(
        'https://api.pdfblocks.com/v1/reorder_pages',
        headers={'X-API-Key': 'your_api_key'},
        files={'file': file},
        data={'page_order': '3,1,2'},
    )

response.raise_for_status()
with open('reordered.pdf', 'wb') as output:
    output.write(response.content)
```

```javascript title="Node.js"
// Node.js 18+
import { readFile, writeFile } from 'node:fs/promises';

const body = new FormData();
body.set('file', new Blob([await readFile('input.pdf')]), 'input.pdf');
body.set('page_order', '3,1,2');

const response = await fetch('https://api.pdfblocks.com/v1/reorder_pages', {
  method: 'POST',
  headers: { 'X-API-Key': 'your_api_key' },
  body,
});

if (!response.ok) throw new Error(`Request failed: ${response.status}`);
await writeFile('reordered.pdf', Buffer.from(await response.arrayBuffer()));
```

```php title="PHP"
<?php
$ch = curl_init('https://api.pdfblocks.com/v1/reorder_pages');
curl_setopt_array($ch, [
    CURLOPT_RETURNTRANSFER => true,
    CURLOPT_HTTPHEADER => ['X-API-Key: your_api_key'],
    CURLOPT_POST => true,
    CURLOPT_POSTFIELDS => [
        'file' => new CURLFile('input.pdf', 'application/pdf'),
        'page_order' => '3,1,2',
    ],
]);

$pdf = curl_exec($ch);
if (curl_getinfo($ch, CURLINFO_HTTP_CODE) === 200) {
    file_put_contents('reordered.pdf', $pdf);
}
```

```ruby title="Ruby"
# gem install http
require 'http'

response = HTTP
  .headers('X-API-Key' => 'your_api_key')
  .post('https://api.pdfblocks.com/v1/reorder_pages', form: {
    file: HTTP::FormData::File.new('input.pdf'),
    page_order: '3,1,2',
  })

File.write('reordered.pdf', response.body) if response.status.success?
```

```go title="Go"
package main

import (
	"bytes"
	"io"
	"mime/multipart"
	"net/http"
	"os"
)

func main() {
	var buf bytes.Buffer
	form := multipart.NewWriter(&buf)

	file, _ := os.Open("input.pdf")
	defer file.Close()
	part, _ := form.CreateFormFile("file", "input.pdf")
	io.Copy(part, file)

	form.WriteField("page_order", "3,1,2")
	form.Close()

	req, _ := http.NewRequest("POST", "https://api.pdfblocks.com/v1/reorder_pages", &buf)
	req.Header.Set("Content-Type", form.FormDataContentType())
	req.Header.Set("X-API-Key", "your_api_key")

	res, _ := http.DefaultClient.Do(req)
	defer res.Body.Close()

	out, _ := os.Create("reordered.pdf")
	defer out.Close()
	io.Copy(out, res.Body)
}
```

```csharp title="C#"
using var client = new HttpClient();
client.DefaultRequestHeaders.Add("X-API-Key", "your_api_key");

using var form = new MultipartFormDataContent
{
    { new ByteArrayContent(File.ReadAllBytes("input.pdf")), "file", "input.pdf" },
    { new StringContent("3,1,2"), "page_order" },
};

var response = await client.PostAsync(
    "https://api.pdfblocks.com/v1/reorder_pages", form);
response.EnsureSuccessStatusCode();
await File.WriteAllBytesAsync(
    "reordered.pdf", await response.Content.ReadAsByteArrayAsync());
```

</CodeGroup>

## Response

On success, the response is `200 OK` with the reordered PDF as the body:

```http
HTTP/1.1 200 OK
Content-Type: application/pdf
Content-Length: 39184
```

Stream the body straight to a file, as the examples above do; nothing is stored
on our side.

## Errors

Failed requests return an `application/problem+json` body. The most common one
for this endpoint is a `400`, returned when `page_order` is malformed or names a
page the document doesn't have — the `errors` object identifies the field:

```json
{
  "type": "https://www.pdfblocks.com/docs/api/v1/error/400",
  "title": "One or more validation errors occurred.",
  "status": 400,
  "errors": {
    "page_order": ["The page_order field references a page that does not exist in the document."]
  }
}
```

A missing or invalid `X-API-Key` returns a `401`. See
[Errors](/docs/api/errors) for every status code and the full response shape.

## Recipes

Common variations. Expand one to see it in every language.

<AccordionGroup>

<Accordion title="Move the last page to the front">

<CodeGroup>

```bash title="cURL"
curl https://api.pdfblocks.com/v1/reorder_pages \
  -H 'X-API-Key: your_api_key' \
  -F file=@input.pdf \
  -F page_order='-1,1..-2' \
  -o last-first.pdf
```

```python title="Python"
import requests

with open('input.pdf', 'rb') as file:
    response = requests.post(
        'https://api.pdfblocks.com/v1/reorder_pages',
        headers={'X-API-Key': 'your_api_key'},
        files={'file': file},
        data={'page_order': '-1,1..-2'},
    )

response.raise_for_status()
with open('last-first.pdf', 'wb') as output:
    output.write(response.content)
```

```javascript title="Node.js"
import { readFile, writeFile } from 'node:fs/promises';

const body = new FormData();
body.set('file', new Blob([await readFile('input.pdf')]), 'input.pdf');
body.set('page_order', '-1,1..-2');

const response = await fetch('https://api.pdfblocks.com/v1/reorder_pages', {
  method: 'POST',
  headers: { 'X-API-Key': 'your_api_key' },
  body,
});

if (!response.ok) throw new Error(`Request failed: ${response.status}`);
await writeFile('last-first.pdf', Buffer.from(await response.arrayBuffer()));
```

```php title="PHP"
<?php
$ch = curl_init('https://api.pdfblocks.com/v1/reorder_pages');
curl_setopt_array($ch, [
    CURLOPT_RETURNTRANSFER => true,
    CURLOPT_HTTPHEADER => ['X-API-Key: your_api_key'],
    CURLOPT_POST => true,
    CURLOPT_POSTFIELDS => [
        'file' => new CURLFile('input.pdf', 'application/pdf'),
        'page_order' => '-1,1..-2',
    ],
]);

$pdf = curl_exec($ch);
if (curl_getinfo($ch, CURLINFO_HTTP_CODE) === 200) {
    file_put_contents('last-first.pdf', $pdf);
}
```

```ruby title="Ruby"
require 'http'

response = HTTP
  .headers('X-API-Key' => 'your_api_key')
  .post('https://api.pdfblocks.com/v1/reorder_pages', form: {
    file: HTTP::FormData::File.new('input.pdf'),
    page_order: '-1,1..-2',
  })

File.write('last-first.pdf', response.body) if response.status.success?
```

```go title="Go"
package main

import (
	"bytes"
	"io"
	"mime/multipart"
	"net/http"
	"os"
)

func main() {
	var buf bytes.Buffer
	form := multipart.NewWriter(&buf)

	file, _ := os.Open("input.pdf")
	defer file.Close()
	part, _ := form.CreateFormFile("file", "input.pdf")
	io.Copy(part, file)

	form.WriteField("page_order", "-1,1..-2")
	form.Close()

	req, _ := http.NewRequest("POST", "https://api.pdfblocks.com/v1/reorder_pages", &buf)
	req.Header.Set("Content-Type", form.FormDataContentType())
	req.Header.Set("X-API-Key", "your_api_key")

	res, _ := http.DefaultClient.Do(req)
	defer res.Body.Close()

	out, _ := os.Create("last-first.pdf")
	defer out.Close()
	io.Copy(out, res.Body)
}
```

```csharp title="C#"
using var client = new HttpClient();
client.DefaultRequestHeaders.Add("X-API-Key", "your_api_key");

using var form = new MultipartFormDataContent
{
    { new ByteArrayContent(File.ReadAllBytes("input.pdf")), "file", "input.pdf" },
    { new StringContent("-1,1..-2"), "page_order" },
};

var response = await client.PostAsync(
    "https://api.pdfblocks.com/v1/reorder_pages", form);
response.EnsureSuccessStatusCode();
await File.WriteAllBytesAsync(
    "last-first.pdf", await response.Content.ReadAsByteArrayAsync());
```

</CodeGroup>

</Accordion>

<Accordion title="Duplicate the cover page">

<CodeGroup>

```bash title="cURL"
curl https://api.pdfblocks.com/v1/reorder_pages \
  -H 'X-API-Key: your_api_key' \
  -F file=@input.pdf \
  -F page_order='1,1..-1' \
  -o doubled-cover.pdf
```

```python title="Python"
import requests

with open('input.pdf', 'rb') as file:
    response = requests.post(
        'https://api.pdfblocks.com/v1/reorder_pages',
        headers={'X-API-Key': 'your_api_key'},
        files={'file': file},
        data={'page_order': '1,1..-1'},
    )

response.raise_for_status()
with open('doubled-cover.pdf', 'wb') as output:
    output.write(response.content)
```

```javascript title="Node.js"
import { readFile, writeFile } from 'node:fs/promises';

const body = new FormData();
body.set('file', new Blob([await readFile('input.pdf')]), 'input.pdf');
body.set('page_order', '1,1..-1');

const response = await fetch('https://api.pdfblocks.com/v1/reorder_pages', {
  method: 'POST',
  headers: { 'X-API-Key': 'your_api_key' },
  body,
});

if (!response.ok) throw new Error(`Request failed: ${response.status}`);
await writeFile('doubled-cover.pdf', Buffer.from(await response.arrayBuffer()));
```

```php title="PHP"
<?php
$ch = curl_init('https://api.pdfblocks.com/v1/reorder_pages');
curl_setopt_array($ch, [
    CURLOPT_RETURNTRANSFER => true,
    CURLOPT_HTTPHEADER => ['X-API-Key: your_api_key'],
    CURLOPT_POST => true,
    CURLOPT_POSTFIELDS => [
        'file' => new CURLFile('input.pdf', 'application/pdf'),
        'page_order' => '1,1..-1',
    ],
]);

$pdf = curl_exec($ch);
if (curl_getinfo($ch, CURLINFO_HTTP_CODE) === 200) {
    file_put_contents('doubled-cover.pdf', $pdf);
}
```

```ruby title="Ruby"
require 'http'

response = HTTP
  .headers('X-API-Key' => 'your_api_key')
  .post('https://api.pdfblocks.com/v1/reorder_pages', form: {
    file: HTTP::FormData::File.new('input.pdf'),
    page_order: '1,1..-1',
  })

File.write('doubled-cover.pdf', response.body) if response.status.success?
```

```go title="Go"
package main

import (
	"bytes"
	"io"
	"mime/multipart"
	"net/http"
	"os"
)

func main() {
	var buf bytes.Buffer
	form := multipart.NewWriter(&buf)

	file, _ := os.Open("input.pdf")
	defer file.Close()
	part, _ := form.CreateFormFile("file", "input.pdf")
	io.Copy(part, file)

	form.WriteField("page_order", "1,1..-1")
	form.Close()

	req, _ := http.NewRequest("POST", "https://api.pdfblocks.com/v1/reorder_pages", &buf)
	req.Header.Set("Content-Type", form.FormDataContentType())
	req.Header.Set("X-API-Key", "your_api_key")

	res, _ := http.DefaultClient.Do(req)
	defer res.Body.Close()

	out, _ := os.Create("doubled-cover.pdf")
	defer out.Close()
	io.Copy(out, res.Body)
}
```

```csharp title="C#"
using var client = new HttpClient();
client.DefaultRequestHeaders.Add("X-API-Key", "your_api_key");

using var form = new MultipartFormDataContent
{
    { new ByteArrayContent(File.ReadAllBytes("input.pdf")), "file", "input.pdf" },
    { new StringContent("1,1..-1"), "page_order" },
};

var response = await client.PostAsync(
    "https://api.pdfblocks.com/v1/reorder_pages", form);
response.EnsureSuccessStatusCode();
await File.WriteAllBytesAsync(
    "doubled-cover.pdf", await response.Content.ReadAsByteArrayAsync());
```

</CodeGroup>

</Accordion>

</AccordionGroup>

## Related actions

<CardGroup cols={2}>

<Card title="Extract pages" href="/docs/api/extract-pages-from-pdf">
  Keep a subset without reordering (order-free).
</Card>

<Card title="Remove pages" href="/docs/api/remove-pages-from-pdf">
  Drop specific pages.
</Card>

<Card title="Reverse pages" href="/docs/api/reverse-pages-of-pdf">
  Reverse the whole document.
</Card>

<Card title="Merge documents" href="/docs/api/merge-pdf-documents">
  Combine multiple PDFs first.
</Card>

</CardGroup>