Gotenberg
Gotenberg is an open-source, Docker-first HTTP API for converting HTML, Markdown, Office documents, and images into PDFs. It bundles Chromium and LibreOffice in a self-contained image, making it straightforward to run in containers and orchestrators. The API is stateless and designed for automation: send files via multipart/form-data, receive a PDF, optionally with async callbacks.
This tool is for engineering teams that need reliable, programmatic document generation without relying on third-party SaaS. It fits organizations prioritizing data residency, cost control, and operational ownership—especially those already running workloads on Docker, Kubernetes, or serverless platforms with HTTP integrations.
Use Cases
- Backend services generating invoices, statements, reports, labels, or mailings from HTML templates.
- Converting DOCX, ODT, PPTX, and images to PDF for archival or customer delivery.
- Composing multi-part documents server-side by merging several PDFs into one.
- Event-driven pipelines using async conversions and webhooks to avoid blocking requests.
- Platforms needing a self-hosted alternative to managed PDF APIs due to compliance or cost.
- CI/CD and batch jobs that standardize outputs and filenames for downstream storage or distribution.
Strengths
- Containerized and self-contained: Official Docker image includes Chromium, LibreOffice, and dependencies—easy to run locally or in Kubernetes.
- Simple HTTP API: Stateless REST endpoints accept HTML, ZIPs, Office files, and images via multipart/form-data and return PDFs.
- High-fidelity HTML rendering: Chromium-based engine supports modern CSS, webfonts, headers/footers, and page sizing.
- Office document support: LibreOffice handles common formats (DOCX, ODT, PPTX, and more) without proprietary services.
- Async workflows: Built-in asynchronous processing and webhooks with configurable headers and methods.
- Operational controls: Configuration via environment variables/flags; request tracing and custom headers for observability.
- Performance features: HTTP/2 (including h2c) improves throughput and multiplexing on compatible stacks.
- PDF tools: Endpoints for merging PDFs and controlling output order; filename and extension management.
- Modular and extensible: Enable/disable modules and extend the image for custom routes or tools.
- Open-source (MIT): No vendor lock-in; audit and modify the source as needed.
- Solid documentation: Troubleshooting and scalability guidance covering concurrency, timeouts, and resource tuning.
Limitations
- LibreOffice overhead: Conversions may incur ~2–3 seconds of extra latency compared with optimized dedicated services.
- Chromium quirks at scale: High concurrency can trigger rendering issues (duplicated images, clipped content, large outputs); per-instance job limits and horizontal scaling are often necessary.
- Resource sensitivity: Large or complex documents can cause timeouts and high memory usage; requires careful tuning of timeouts, memory, and concurrency.
- Self-hosting burden: No official managed service; you own deployment, monitoring, upgrades, and incident response.
- Edge cases and active issues: Some rendering and platform-specific bugs may require workarounds and staying current with releases.
Final Thoughts
Gotenberg is a pragmatic choice for teams that want a self-hosted, API-driven PDF generator with strong HTML fidelity and broad format support. It integrates cleanly into backend and event-driven systems, and the containerized distribution speeds up adoption.
For production, start with conservative concurrency, tune timeouts and memory, and scale horizontally under load. Use async routes and webhooks for long-running jobs, rely on request tracing to correlate logs and callbacks, and test templates across your expected range of inputs. If you require a fully managed service with strict SLAs or ultra-low-latency Office conversions, consider a hosted alternative.