PDF API

Call 4uPDF's PDF engine from your own apps over a simple HTTP API: high-DPI figure extraction (region → PNG, batch, OCR), core operations (merge, split, compress, PDF-to-JPG), Office conversions (PDF ↔ Word/Excel/PowerPoint) and an OCR searchable-text layer.

Getting a key

The API is available on the Goldplan. Once you're on Gold, open your Dashboard → API Keys, create a key, and copy it (it is shown only once). See Pricing to upgrade.

Authentication

Send your key in the X-API-Key header on every request. Requests without a valid key get 401; a plan without API access gets 403.

X-API-Key: pdf_live_<your_api_key>

Selection coordinates

The region is given as page fractions with a top-left origin: fx0,fy0 is the top-left corner and fx1,fy1 the bottom-right, each between 0 and 1. So the left half of a page is fx0=0, fy0=0, fx1=0.5, fy1=1.

Endpoints

POST /api/v1/extract-region

Render one page region to a high-DPI PNG. Returns image/png.

curl -X POST https://4updf.com/api/v1/extract-region \
  -H "X-API-Key: $KEY" \
  -F "file=@report.pdf" \
  -F "page=1" \
  -F "fx0=0.1" -F "fy0=0.3" -F "fx1=0.7" -F "fy1=0.4" \
  -F "dpi=600" \
  -o figure.png

Fields: file (PDF), page (1-based), fx0/fy0/fx1/fy1, dpi (72–1200, default 300), fmt (png|tiff, default png), transparent (bool), trim (bool, auto-trim a uniform border).

POST /api/v1/extract-region-svg

Export a page region as a scalable vector image/svg+xml — text and vector art stay crisp at any size.

curl -X POST https://4updf.com/api/v1/extract-region-svg \
  -H "X-API-Key: $KEY" \
  -F "file=@report.pdf" \
  -F "page=1" \
  -F "fx0=0.1" -F "fy0=0.3" -F "fx1=0.7" -F "fy1=0.4" \
  -o figure.svg

POST /api/v1/extract-region-batch

Apply the same region across a page range. Returns a application/zip of PNGs.

curl -X POST https://4updf.com/api/v1/extract-region-batch \
  -H "X-API-Key: $KEY" \
  -F "file=@report.pdf" \
  -F "fx0=0.1" -F "fy0=0.3" -F "fx1=0.7" -F "fy1=0.4" \
  -F "dpi=300" \
  -F "page_from=1" -F "page_to=0" \
  -o figures.zip

page_to=0 means "through the last page". Up to 200 pages per request. Also accepts fmt (png|tiff), transparent, trim.

POST /api/v1/extract-region-ocr

OCR the selected region. Returns JSON { text, lines }.

curl -X POST https://4updf.com/api/v1/extract-region-ocr \
  -H "X-API-Key: $KEY" \
  -F "file=@report.pdf" \
  -F "page=1" \
  -F "fx0=0.1" -F "fy0=0.3" -F "fx1=0.7" -F "fy1=0.4"

# => { "text": "Figure 1: ...", "lines": ["Figure 1: ...", ...] }

OCR DPI is clamped to 150–600 (accuracy plateaus above that).

POST /api/v1/merge

Merge 2+ PDFs into one. Returns application/pdf.

curl -X POST https://4updf.com/api/v1/merge \
  -H "X-API-Key: $KEY" \
  -F "files=@a.pdf" -F "files=@b.pdf" \
  -o merged.pdf

Up to 50 files; combined size follows your plan's limit.

POST /api/v1/split

Split a PDF by page ranges. Returns a application/zip of PDFs.

curl -X POST https://4updf.com/api/v1/split \
  -H "X-API-Key: $KEY" \
  -F "file=@doc.pdf" \
  -F "ranges=1-3,4,5-7" \
  -o split.zip

ranges=all (default) splits into single pages. Each comma part becomes one output PDF.

POST /api/v1/compress

Compress a PDF. Returns application/pdf.

curl -X POST https://4updf.com/api/v1/compress \
  -H "X-API-Key: $KEY" \
  -F "file=@doc.pdf" \
  -F "quality=medium" \
  -o compressed.pdf

quality = low | medium | high (default medium).

POST /api/v1/pdf-to-jpg

Render PDF pages to JPGs. Returns a application/zip of images.

curl -X POST https://4updf.com/api/v1/pdf-to-jpg \
  -H "X-API-Key: $KEY" \
  -F "file=@doc.pdf" \
  -F "dpi=150" -F "pages=all" \
  -o images.zip

dpi 36–300 (default 150), pages = all or e.g. 1,3,5-7.

POST /api/v1/pdf-to-word

Extract a PDF's text into an editable Word DOCX. Returns a .docx.

curl -X POST https://4updf.com/api/v1/pdf-to-word \
  -H "X-API-Key: $KEY" \
  -F "file=@doc.pdf" \
  -o converted.docx

POST /api/v1/word-to-pdf

Convert a Word DOCX to PDF. Returns application/pdf.

curl -X POST https://4updf.com/api/v1/word-to-pdf \
  -H "X-API-Key: $KEY" \
  -F "file=@doc.docx" \
  -o converted.pdf

POST /api/v1/pdf-to-excel

Extract PDF tables/text into an Excel XLSX. Returns a .xlsx.

curl -X POST https://4updf.com/api/v1/pdf-to-excel \
  -H "X-API-Key: $KEY" \
  -F "file=@statement.pdf" \
  -o converted.xlsx

Detected tables are preserved; otherwise text is laid out by whitespace columns.

POST /api/v1/excel-to-pdf

Convert an Excel XLSX to PDF. Returns application/pdf.

curl -X POST https://4updf.com/api/v1/excel-to-pdf \
  -H "X-API-Key: $KEY" \
  -F "file=@sheet.xlsx" \
  -o converted.pdf

POST /api/v1/pdf-to-powerpoint

Render each PDF page as a slide in a PowerPoint PPTX. Returns a .pptx.

curl -X POST https://4updf.com/api/v1/pdf-to-powerpoint \
  -H "X-API-Key: $KEY" \
  -F "file=@deck.pdf" \
  -o converted.pptx

POST /api/v1/powerpoint-to-pdf

Convert a PowerPoint PPTX to PDF. Returns application/pdf.

curl -X POST https://4updf.com/api/v1/powerpoint-to-pdf \
  -H "X-API-Key: $KEY" \
  -F "file=@deck.pptx" \
  -o converted.pdf

POST /api/v1/ocr-pdf

Add a searchable OCR text layer to a scanned PDF (text becomes selectable/searchable). Returns application/pdf.

curl -X POST https://4updf.com/api/v1/ocr-pdf \
  -H "X-API-Key: $KEY" \
  -F "file=@scan.pdf" \
  -F "dpi=300" \
  -o searchable.pdf

dpi 150–400 (default 300). Up to 100 pages per request.

Limits & errors

Monthly call quota is included with your plan (Gold: 10,000 calls/month). When it's reached you get 429 until the next month — there is no overage billing.
Max file size follows your plan's limit; oversize uploads return 413.
A degenerate selection, an out-of-range page, or a region too large at the chosen DPI returns 400.
Password-protected PDFs are not supported (400) — remove the password first.
Office conversions are limited to 200 pages per request, and OCR to 100 pages (400 over the cap) — split large files first.

Ready to build?

Upgrade to Gold, create a key, and make your first call in minutes.

View pricing Go to dashboard