Stirling-PDF: The PDF Toolbox on Your Own Server

“Merge PDF online”, “compress PDF free” – for tasks like these you’d usually upload your documents to some web service, often with confidential content. Stirling-PDF does the same on your own server: over 50 PDF tools, and your files never leave your control.

What are we building?

A complete PDF toolbox with Stirling-PDF v2.14.2 behind Traefik, secured with a login. By the end you merge PDFs, compress and rotate them, convert between formats, make scanned documents searchable with OCR, redact content, add passwords or watermarks – all in the browser, all locally. Exactly the right tool to prepare documents from Paperless or Nextcloud.

Prerequisites

• A server with Traefik running and Docker Compose
• A subdomain pointing at the server – YOUR_DOMAIN below

Step by step

Step 1: Project and Compose file

Stirling-PDF is stateless at its core – it processes files and returns them without storing them permanently. Only configuration and OCR language data live in volumes. Create the project:

mkdir -p /opt/stirling/data /opt/stirling/configs && cd /opt/stirling

The compose.yaml – replace YOUR_DOMAIN:

services:
  stirling-pdf:
    image: stirlingtools/stirling-pdf:2.14.2
    restart: unless-stopped
    volumes:
      - ./data:/usr/share/tessdata   # OCR language data
      - ./configs:/configs           # configuration
    environment:
      LANGS: 'en_GB'                  # UI language
    networks: [proxy]
    labels:
      - "traefik.enable=true"
      - "traefik.http.routers.stirling.rule=Host(`YOUR_DOMAIN`)"
      - "traefik.http.routers.stirling.entrypoints=websecure"
      - "traefik.http.routers.stirling.tls.certresolver=le"
      - "traefik.http.services.stirling.loadbalancer.server.port=8080"

networks:
  proxy:
    external: true

Step 2: Start and wait for “healthy”

docker compose up -d

The image ships its own health check, and Traefik only routes to the container once it’s healthy – which takes about 20–30 seconds after start (the Java application needs a moment). Check:

docker compose ps

NAME                      IMAGE                              STATUS
stirling-stirling-pdf-1   stirlingtools/stirling-pdf:2.14.2  Up (healthy)

Step 3: First login and forced password change

Open https://YOUR_DOMAIN/. Stirling-PDF v2 is protected by a login by default – an important difference from many other tools, and one you shouldn’t disable if the service is publicly reachable.

Log in with the default credentials admin / stirling. On first login Stirling-PDF immediately forces a password change – good. Set a strong password; then log in again with the new one.

Step 4: The toolbox

After login you see the interface: your files on the left, the full tool catalog on the right, grouped into categories like Signing, Document security and Verification.

Getting started is always the same: load a PDF via Upload from computer (or drag & drop), then pick the tool you want on the right. The file appears in the built-in viewer:

The most useful tools in everyday use:

• Merge / Split: combine multiple PDFs into one or separate out pages.
• Compress: reduce file size for sending by email.
• Convert: PDF ↔ image, Word/Office → PDF and back.
• OCR & clean scans: make scanned documents searchable (that’s what the tessdata language data is for).
• Redact: permanently remove confidential parts – not just paint over them in black.

Step 5: Add OCR languages (optional)

For OCR in a given language, Stirling-PDF needs the matching Tesseract language data. The official image ships common languages; if one is missing, drop the corresponding .traineddata file into the mounted data folder (/usr/share/tessdata). After that the language is available in the OCR tool.

When things go wrong

Maintenance & backups

• Updates. Occasionally bump the image tag (stirlingtools/stirling-pdf:2.14.2) to the current version and docker compose up -d. Stirling-PDF is actively developed and gets new tools frequently; a look at the release notes is worthwhile. The rest runs through your normal update process.
• The backup is small. Because the file processing is stateless, you only need to back up the configs folder (login, settings) and any custom OCR language data – best with Restic. You store the processed PDFs yourself anyway.
• Security. The login is the first line of defense – keep the admin password strong and current. Since potentially confidential documents pass through here, running behind HTTPS (Traefik) and a login is mandatory; a publicly reachable Stirling-PDF without a password would be a serious data leak.