---
name: "pdf123-remove-blanks"
description: "Detect and delete blank pages. Runs the PDF123 \"Remove Blanks\" 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: 删除空白页, Quitar páginas en blanco, खाली पृष्ठ हटाएँ, حذف الصفحات الفارغة, Remover páginas em branco, Hapus halaman kosong, Supprimer les pages blanches, Удалить пустые страницы, 空白ページの削除, Leere Seiten entfernen, 빈 페이지 삭제, Xóa trang trống, Boş sayfaları sil, 刪除空白頁, Rimuovi pagine vuote, ลบหน้าว่าง, Usuń puste strony, Прибрати порожні сторінки, Lege pagina's verwijderen, Buang halaman kosong, Ta bort tomma sidor, Αφαίρεση κενών σελίδων, Премахване на празни страници, Treu pàgines en blanc, Ondoa kurasa tupu."
compatibility: "Needs curl 7.76+ and outbound HTTPS to pdf123.xyz, or PDFX_API_BASE pointing at a self-hosted pdfx-server."
---

# Remove Blanks (PDF123)

Detect and delete blank pages.

Web version: https://pdf123.xyz/remove-blanks · All tools: https://pdf123.xyz/skills/pdf123.md

## When to use

- Pull text-empty separator pages out of a born-digital export
- Keep image scans together even when they look white
- Inspect both ZIP entries before deleting anything

## 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/misc/remove-blanks" \
  -F "fileInput=@input.pdf" \
  -F "threshold=10" \
  -F "whitePercent=99.9" \
  --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) |
| `threshold` | text | no | `10` | Blank detection threshold |
| `whitePercent` | text | no | `99.9` | White percentage threshold |

## 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

- Not visual whitespace detection
- Not OCR
- whitePercent unused
- 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`.