AltFreeStack
ESEN
Dev Toolsdocker-readypermissive-licenseOpen-Core🟢 Lightweight · ~256MB

Stirling PDF: Open-Core alternative to Adobe Acrobat in 2026

Stirling PDF is a self-hosted Swiss army knife for PDFs: merge, split, compress, sign, convert and OCR, all from a web interface without uploading your documents to a third party.

Core is open source, but advanced features or enterprise support may be behind a paid tier — check the license.

Alternative to Adobe AcrobatAlternative to Smallpdf
License MIT94.1k starsWebsite GitHub Repository

Audit Snapshot

View notes →

  • License — Not verifiable on GitHub

  • GitHub — Active

  • Latest release — v3.1.0 · 7 days ago

  • Docker Compose — Not verified

  • Production — Not production-tested by AltFreeStack

Stirling PDF vs. Adobe Acrobat

Pros

  • Your documents never leave your own server

Things to consider

  • The interface is functional but less polished than commercial tools

Quick Docker installation guide

Copy this docker-compose.yml, adjust the example passwords and run docker compose up -d on your server. See the full step-by-step guide →

💡 Official SaaS or self-hosted with AltFreeStack?

  • On the official cloud: a recurring monthly fee and usage limits on Adobe Acrobat.
  • On your own VPS: the core is free to self-host on your own server — no more monthly SaaS fee, though some advanced features stay behind a paid plan.
docker-compose.yml
services:
  stirling-pdf:
    image: stirlingtools/stirling-pdf:latest
    ports:
      - "8080:8080"
    environment:
      DOCKER_ENABLE_SECURITY: "false"
    volumes:
      - ./trainingData:/usr/share/tessdata
      - ./extraConfigs:/configs

🚀 Deploy in 1 command

Recommended for beginners

Copy this single command and paste it into your freshly created VPS's console (Vultr, DigitalOcean...). It downloads the script, prints it to your screen so you can see exactly what it's about to do (never a blind direct pipe), and only then installs Docker if needed, writes the files with secrets already generated, and starts everything — no nano, no pasting code blocks.

curl -sSL ".../api/deploy?stack=stirling-pdf" -o deploy.sh && cat deploy.sh && bash deploy.sh
See what this script does →

This docker-compose corresponds to an actively maintained project — last commit today.

This docker-compose not working for you? Report it on GitHub →

Technical profile

License
MIT
Category
Dev Tools
Replaces
Adobe Acrobat, Smallpdf
Tech stack
JavaSpring Boot

Key features

  • Over 50 different PDF operations
  • Built-in OCR (Tesseract)
  • Digital signing and password protection
💾 Backups in 3 steps (Day 2)

As long as the ./data folder (the "volume" mapped into the container) exists on your server, your data survives any restart or container update — that's the only thing you need to back up.

1. Create a compressed backup on the server

tar -czvf backup-$(date +%F).tar.gz ./data

2. Download it to your computer

From your computer's terminal (not your server's):

scp root@YOUR_IP:~/app/backup-*.tar.gz ./

3. Restore in case of emergency

tar -xzvf backup-file.tar.gz
🌐 Connect your domain with free SSL

Step 1 — Set up the DNS

In your domain registrar's dashboard (Cloudflare, Namecheap, GoDaddy...), create a record:

Type
A
Name/Host
@ (root domain) or a subdomain, e.g. app
Content/Value
Your server's public IP

Wait 5 to 15 minutes for the record to propagate across the internet.

Step 2 — Automatic reverse proxy with Caddy

One single file, no Nginx config or manual certificates — Caddy issues and renews Let's Encrypt HTTPS on its own.

Create a file called Caddyfile:

yourdomain.com {
    reverse_proxy localhost:8080
}

Start Caddy with this command (pulls the image and runs it in the background):

docker run -d -p 80:80 -p 443:443 --name caddy --restart always -v $PWD/Caddyfile:/etc/caddy/Caddyfile -v caddy_data:/data caddy