PDF API Hub
Add text, watermarks, and fill forms in pdfs with ease | API
What it does
Easily add text, fill fields, and apply watermarks to PDFs using our simple API. PDF API Hub is developer-friendly and integration-ready.
Does a similar job
all alternatives →- AAAn API for filling out PDF forms2017 · formapi.io · ▲209


- PAPDF API – Generate, convert, and modify PDF documents2022 · ▲204
Hi HN, Arek here. We’re super excited to officially launch PSPDFKit API [1]. PSPDFKit API is a collection of HTTP APIs that enable you to convert, generate, and edit documents without running any service on your infrastructure. What differentiates our API from others is that you can chain together multiple “actions” as part of a single API request. For example, you can convert, OCR, watermark, edit, and flatten a document — all in one call. Available actions [2]: - PDF Generator - PDF Converter - Image Converter - OCR - Watermark - Merge - Split - Duplicate - Delete - Flatten Our…


More dev tools this month
the category →



OpenTrailPaper is open-source bike computer firmware for the LilyGO T5S3 4.7" E-Paper PRO. It supports offline maps, GPX routes, FIT recording and Bluetooth sensors.
Dev tools · 3d ago · opentrailpaper.com

Open-source GTM skills for technical founders
Dev tools · 30d ago · gtmcofounder.com

Launched alongside, August 2025
the whole month →
- IS
I built the world's most impractical 1000-pixel display and anyone in the world can draw on it. It draws a single pixel at a time and takes 30-60 minutes to complete a single image. Anyone can participate in the project by voting for the next image to be drawn, and submitting images. https://kilopx.com/
Work · 2025 · benholmen.com

- KT
Kitten TTS is an open-source series of tiny and expressive text-to-speech models for on-device applications. We are excited to launch a preview of our smallest model, which is less than 25 MB. This model has 15M parameters. This release supports English text-to-speech applications in eight voices: four male and four female. The model is quantized to int8 + fp16, and it uses onnx for runtime. The model is designed to run literally anywhere eg. raspberry pi, low-end smartphones, wearables, browsers etc. No GPU required! We're releasing this to give early users a sense of the latency and voices…
Dev tools · 2025 · github.com
- IW
I was wondering how I can arrange objects along a spherical helix path, and read some articles on it. I ended up learning about parametric equations again, and make this visualization to document what I learned: https://visualrambling.space/moving-objects-in-3d/ feel free to visit and let me know what you think!
Life & fun · 2025 · visualrambling.space
- TC
For HTML Day 2025 [1], I made a web service that displays the current sky at your approximate location as a CSS gradient. Colours are simulated on-demand using atmospheric absorption and scattering coefficients. Updates every minute, without the use of client-side JavaScript. Source code and additional information is available on GitHub: https://github.com/dnlzro/horizon [1] https://html.energy/html-day/2025/index.html
Dev tools · 2025 · sky.dlazaro.ca