---
name: "pdf123-split-by-chapters"
description: "Split a PDF along its bookmark/chapter structure. Runs the PDF123 \"Split PDF by Chapters\" tool (pdf123.xyz) over its REST API with curl, no account needed. Use when the user wants this done to their file. Also known as: 按章节拆分, Dividir PDF por capítulos, अध्यायों से बाँटें, تقسيم حسب الفصول, Pisah PDF menurut bab, Diviser le PDF par chapitres, Разделить по главам, 章ごとに分割, Nach Kapiteln teilen, 장별로 분할, Tách theo chương, Bölümlere göre böl, 依章節分割, Dividi PDF per capitoli, แยกตามบท, Podziel według rozdziałów, Розрізати за розділами, Splitsen op hoofdstukken, Asingkan PDF mengikut bab, Dela efter kapitel, Διαχωρισμός κατά κεφάλαια, Разделяне по глави, Parteix per capítols, Gawanya kwa sura."
compatibility: "Needs curl 7.76+ and outbound HTTPS to pdf123.xyz, or PDFX_API_BASE pointing at a self-hosted pdfx-server."
---

# Split PDF by Chapters (PDF123)

Split a PDF along its bookmark/chapter structure.

Web version: https://pdf123.xyz/split-by-chapters · All tools: https://pdf123.xyz/skills/pdf123.md

## When to use

- Cut a book that already has a proper outline into chapter files
- Split a report whose bookmarks match real sections
- Avoid guessing chapter starts from heading text

## Run it

Replace the sample file names and values with the user's, then run:

```bash
API="${PDFX_API_BASE:-https://pdf123.xyz}"
curl -sS --fail-with-body -X POST "$API/api/v1/general/split-pdf-by-chapters" \
  -F "fileInput=@input.pdf" \
  --output-dir "pdf123-output/$(date +%Y%m%d-%H%M%S)" --create-dirs -OJ -w '%{filename_effective} %{content_type}\n'
```

## Inputs

Everything is `multipart/form-data`. The command above already sends each field with its default; keep them all and change only the values the user asked for, since some endpoints reject a missing optional field.

| Field | Type | Required | Default | Notes |
| --- | --- | --- | --- | --- |
| `fileInput` | file | yes | | .pdf (one file) |

## Result

curl saves the result in a new `pdf123-output/<timestamp>/` directory under the server's file name and prints its path and content type. Several output files come back as one ZIP. Tell the user where the file is.

## Limits

- Requires /Outlines
- Top level only
- Not OCR
- Upload limit on this website: 500 MB per file, sent in chunks above about 95 MB. A single direct API request body is capped at 100 MB.

## Errors

- A non-zero curl exit means the request failed. The saved file then holds `application/problem+json`; read it and report its `detail` to the user instead of retrying blindly.
- `413`: the upload exceeds 100 MiB. `429`: wait for `Retry-After` seconds, then retry once.
- Send `X-API-KEY: $PDFX_API_KEY` only if the user has a PDF123 API key; anonymous calls work without it.

## Privacy

Files are uploaded to the API host, processed, and deleted once the response is sent. For confidential files, ask before uploading, or use a self-hosted server via `PDFX_API_BASE`.