What Are PDF Processing Tools?
Mix (6 tools)
- License: 6 open source · 0 proprietary
- Hosting: 6 self-hosted · 0 SaaS · 0 both
PDF processing tools provide web-based or API-driven operations on PDF documents: merging, splitting, converting, compressing, signing, OCR, watermarking, and more. Unlike a Document Management System (DMS) that organizes and stores documents, PDF tools focus on transforming documents – they are utilities, not archives.
Key capabilities:
- Merge / split – combine multiple PDFs or extract pages
- Convert – HTML/Office/images to PDF and back
- OCR – add searchable text layers to scanned PDFs
- Compress – reduce file size for storage or email
- Sign – add digital or visual signatures
- Watermark – overlay text or images
- Redact – permanently remove sensitive content
- Batch processing – apply operations to many files at once
- Form handling – fill, flatten, or extract form data
About this data & disclaimer
The information on these pages was researched by a combination of human review and large language models. This catalogue serves as a reference for the resources, applications, devices, deployment payloads, and other components that the ResorsIT platform integrates, deploys, and manages. To suggest an addition or correction, please contact us. Prepared by Rhodium Systems Inc., author of the ResorsIT platform — a unified IT operations management platform for IT teams and MSPs that integrates a curated suite of open-source, commercial, and SaaS applications into a single system with shared identity, single sign-on, access control, and a common audit trail. This information is compiled on a best-effort basis: it may be incomplete, contain errors, and become out of date as tools, vendors, licences, and features change. Use this catalogue only as a starting point for your own research, and independently verify and review any tool carefully against your own requirements before relying on it.
Comparison
SSO / OIDC Comparison
OIDC is the preferred SSO protocol.
| Tool | OIDC | SAML | LDAP | Authentik Notes |
|---|---|---|---|---|
| Stirling-PDF | Pro* | No | No | Free: reverse-proxy auth; Pro: native OIDC |
| BentoPDF | No | No | No | Reverse-proxy auth only (static app) |
| Gotenberg | N/A | N/A | N/A | API service; basic auth or network ACL |
| SignaturePDF | No | No | No | Reverse-proxy auth only |
| ComPDF | No | No | No | Reverse-proxy auth; local admin + API keys |
| PdfCraft | N/A | N/A | N/A | Desktop app; no auth surface |
* = requires commercial Pro tier
Best SSO support: Stirling-PDF Pro (native OIDC); all others rely on reverse-proxy authentication via Traefik + Authentik forward-auth.
Gotenberg: SSO is not applicable – it is an API-only service with no user interface.
API Comparison
| Tool | API Type | Auth | Webhooks | Batch |
|---|---|---|---|---|
| Stirling-PDF | REST | API key / session | No | Yes |
| BentoPDF | None | N/A | No | No |
| Gotenberg | REST | Basic auth | Yes | Yes |
| SignaturePDF | None | N/A | No | No |
| ComPDF | REST | API key | No | No |
| PdfCraft | None | N/A | No | Yes |
Best API: Gotenberg (purpose-built API with webhook support); Stirling-PDF (comprehensive REST API covering all 60+ operations).
No API: BentoPDF (client-side only) and SignaturePDF (browser-only).
Feature Matrix
| Feature | Stirling-PDF | BentoPDF | Gotenberg | SignaturePDF | ComPDF | PdfCraft |
|---|---|---|---|---|---|---|
| Merge | Yes | Yes | Yes | No | Yes | Yes |
| Split | Yes | Yes | No | No | Yes | Yes |
| Convert to PDF | Yes | Images | Yes | No | Yes | No |
| Convert from PDF | Yes | Images | No | No | Yes | No |
| OCR | Yes | No | No | No | Yes | No |
| Sign | Yes | Yes | No | Yes | No | No |
| Compress | Yes | Yes | No | No | No | No |
| Watermark | Yes | Yes | No | No | Yes | No |
| Redact | Yes | No | No | No | No | No |
| Encrypt/Decrypt | Yes | Yes | No | No | Yes | Read |
| Form handling | Yes | Flatten | No | No | No | Preserve |
| Batch processing | Yes | No | Yes | No | No | CLI |
| Page operations | Yes | Yes | No | Basic | Yes | Yes |
Most complete: Stirling-PDF (60+ operations).
Conversion specialist: Gotenberg (Chromium + LibreOffice; best for automated pipelines).
Privacy-first: BentoPDF (all processing in browser via WASM; no server upload).
Signing-only: SignaturePDF (minimal scope).
Processing Model
| Tool | Model | Privacy | Large Files |
|---|---|---|---|
| Stirling-PDF | Server-side | Docs uploaded to server | Good (server resources) |
| BentoPDF | Client-side (WASM) | Docs never leave browser | Limited (~200 MB) |
| Gotenberg | Server-side | Docs uploaded to server | Good (server resources) |
| SignaturePDF | Server-side | Docs uploaded to server | Good (lightweight) |
| ComPDF | Server-side | Docs uploaded to server | Good (server resources) |
| PdfCraft | Local desktop | Docs never leave the machine | Good (local resources) |
Key trade-off: server-side tools (Stirling-PDF, Gotenberg, SignaturePDF) handle large files and complex operations but require document upload. BentoPDF keeps documents local but is constrained by browser resources and cannot run OCR or Office conversion.
Deployment Comparison
| Tool | Docker | ARM64 | Bare Metal | Stateless |
|---|---|---|---|---|
| Stirling-PDF | Yes (3 variants) | Yes | No | Yes |
| BentoPDF | Yes | Yes | Yes (static) | Yes |
| Gotenberg | Yes (only) | Yes | No | Yes |
| SignaturePDF | Yes | Community | Yes (PHP) | Yes |
| ComPDF | Yes (Compose) | — | No | No |
| PdfCraft | No | N/A | Yes (desktop) | Yes |
Stirling-PDF, BentoPDF, Gotenberg, and SignaturePDF are all stateless – they do not store documents permanently, which simplifies deployment, scaling, and backup. ComPDF is the exception: it is a stateful stack (MySQL, Redis, and object storage) that persists data via volumes.
Licensing Comparison
| Tool | License | Free Tier | Paid Tier |
|---|---|---|---|
| Stirling-PDF | MIT (core) | Full UI + API; no OIDC | Pro: $99/mo or $1K/yr; OIDC |
| BentoPDF | AGPL-3.0 | Full features | $49 lifetime commercial license |
| Gotenberg | MIT | Full features | None (fully free) |
| SignaturePDF | AGPL-3.0 | Full features | None (fully free) |
| ComPDF | MIT (core) | Watermark + page limits | Enterprise (contact); watermark-free |
| PdfCraft | Apache-2.0 OR MIT | Full features | None (fully free) |
Most permissive: Gotenberg and Stirling-PDF (MIT) – no copyleft obligations.
AGPL consideration: BentoPDF and SignaturePDF use AGPL-3.0, which requires source disclosure if the software is offered as a network service. This may complicate customer deployments where customers modify the tool.
Tools
6 tools.
BentoPDF
BentoPDF is a privacy-first PDF processing tool that runs entirely in the browser using WebAssembly. Unlike server-side tools like Stirling-PDF, BentoPDF processes all documents on the client – files never leave the user’s device.
License: AGPL-3.0-only (OSS) · Kind: web · Deploy: direct, docker · SSO: none
ResorsIT usage: Web App without SSO
Access & Identity: Forward-auth · Vaulted credential
ComPDF
ComPDF is a self-hosted, open-source PDF processing and conversion platform with a web dashboard and REST API, offering merge, split, OCR, encryption, and PDF/Office/image conversion via Docker Compose.
License: MIT (OSS) · Kind: web · Deploy: docker · SSO: none
ResorsIT usage: Web App without SSO
Access & Identity: Forward-auth · Vaulted credential
Gotenberg
Gotenberg is a stateless, API-only PDF conversion engine. It has no web UI – all operations are performed via REST API calls.
License: MIT (OSS) · Kind: web · Deploy: direct, docker · SSO: none
ResorsIT usage: Web App without SSO
Access & Identity: Forward-auth · Vaulted credential
PdfCraft
PdfCraft is a from-scratch PDF reader and workbench written in pure Rust for reading, organising, combining, splitting and securing files, with structure-preserving edits and a headless CLI.
License: Apache-2.0 OR MIT (OSS) · Kind: desktop · Deploy: package, direct · SSO: none · Tags: pdf, document-tools, rust, desktop, offline
ResorsIT usage: Deployment Payload
Access & Identity: Vaulted credential · Local host account
SignaturePDF
SignaturePDF is a lightweight, single-purpose PDF tool focused on adding signatures to PDF documents. It provides a simple web interface where users open a PDF, draw or place a signature, and download the signed result.
License: AGPL-3.0-only (OSS) · Kind: web · Deploy: direct, docker · SSO: none
ResorsIT usage: Web App without SSO
Access & Identity: Forward-auth · Vaulted credential
Stirling-PDF
Stirling-PDF is the most popular open-source PDF processing tool, with over 50,000 GitHub stars and rapid development.
License: MIT (OSS) · Kind: web · Deploy: direct, docker · SSO: OIDC
ResorsIT usage: Web App with SSO
Access & Identity: Single sign-on
