UIKit
Bootstrap
Semantic UI
Foundation
Materialize CSS
Bulma
Tailwind CSS
Skeleton CSS
Converterer
PDFShift
DocRaptor
pdflayer
HTMLEmail.io
PDFCrowd
Templates by Email Monster
Api2Pdf
Converterer (formerly Paperplane) is a REST API for file conversion and website capture, built for developers and no-code workflows.
File conversion: convert documents, spreadsheets, presentations, images, audio, and video across 300+ format pairs: DOCX to PDF, PDF to DOCX, XLSX to CSV, PNG to WebP, HEIC to JPG, MP4 to GIF, WAV to MP3, and hundreds more. Upload a file or pass a URL, and the converted file is delivered to built-in storage or your own bucket.
Website capture: render any URL as a pixel-perfect, print-ready PDF with a real headless Chromium engine, the same rendering path that has powered Paperplane since 2018. Page size, margins, headers and footers with page numbers, HTTP auth, and wait conditions for JavaScript-heavy pages are all parameters on a single call.
Built for developers: plain REST with curl-friendly endpoints, no SDK needed, just POST it. Code recipes for Python, Node.js, PHP, Laravel, Ruby, Go, Java, and plain cURL. Async jobs with signed (HMAC) webhooks, metadata passthrough, custom file names, and a synchronous capture endpoint when you want the PDF back in one request.
No-code and automation: drop conversion and capture into Zapier, Make, n8n, Power Automate, or Workato flows.
Storage your way: results land in the built-in destination with zero setup, or connect your own bucket (S3-compatible, Google Cloud Storage, Azure, and more).
Pricing: 100 free conversions a month, no credit card required, files up to 1 GB on every plan. Paid plans from $9.99/month including 2,500 conversions.
Formerly Paperplane (est. 2018): same team and infrastructure, expanded from HTML-to-PDF to full file conversion.
UIKit
ConvertererUIKit is recommended for developers who need a flexible and modular framework for building user interfaces, especially those who prefer a clean design system and extensive component library. It is suitable for beginners due to its comprehensible documentation and also for experienced developers looking to streamline their workflow with a reliable front-end framework.
Converterer's answer:
Two APIs under one plan and one allowance: file conversion across 300+ format pairs (documents, spreadsheets, presentations, images, audio, video) and website capture that renders any URL as a print-ready PDF with a real headless Chromium engine. Pricing is flat per conversion, so a 900 MB video costs the same as a 40 KB document, where most competitors bill credits or processing minutes that scale with file size. And there is no SDK to install: it is plain REST you can drive from cURL.
Converterer's answer:
Predictable cost and less integration work. Flat per-conversion pricing with files up to 1 GB on every plan means no surprise bills when documents get heavy. The free tier is a real recurring allowance, 100 conversions every month with no card, rather than a one-time trial. Integration is one POST request with HTTP Basic auth, HMAC-signed webhooks instead of polling, and delivery straight into your own storage bucket if you want it. The capture engine has been rendering PDFs in production since 2018, and we publish sourced, dated comparisons against competitors on our own site, including the cases where they are the better fit.
Converterer's answer:
Developers adding file conversion or document rendering to their products (invoices, reports, archives, media processing), and operations or no-code builders automating the same jobs through Zapier, Make, n8n, Power Automate, or Workato. Typical users are SaaS teams generating documents at scale and teams replacing self-hosted conversion stacks they no longer want to operate.
Converterer's answer:
Converterer started in 2018 as Paperplane, a focused HTML-to-PDF API built on headless Chrome. Customers kept asking for conversions that had nothing to do with HTML: DOCX to PDF, HEIC to JPG, MP4 to GIF. So the platform grew past its name, and in May 2026 it relaunched as Converterer: the same team and rendering engine, expanded to a full file conversion API with 300+ format pairs alongside the original website capture.
Converterer's answer:
Website capture runs on a real headless Chromium engine, so output matches what desktop Chrome renders, including web fonts, Flexbox, Grid, and JavaScript-heavy pages. The API itself is plain REST over HTTPS with HTTP Basic authentication and HMAC-signed webhooks, and output delivery integrates with standard object storage (S3-compatible, Google Cloud Storage, Azure).
Based on our record, UIKit seems to be more popular. It has been mentiond 22 times since March 2021. We are tracking product recommendations and mentions on various public social media platforms and blogs. They can help you identify which product is more popular and what people think of it.
UIkit: A lightweight and modular front-end framework. - Source: dev.to / almost 2 years ago
Franken UI is compatible with UIkit 3 and can work as a standalone CSS framework but can be integrated with Tailwind CSS for faster styling and customization. The design of Franken UI is influenced by shadcn/ui. It aims to provide a solution to developers who are not comfortable using React, Vue, or Svelte by leveraging UIkit for JavaScript and accessibility. - Source: dev.to / about 2 years ago
As an iOS engineer, you've likely encountered SwiftUI and UIkit, two popular tools for building iOS user interfaces. SwiftUI is the new cool kid on the block, providing a clean way to build iOS screens, while UIkit is the older and more traditional way to build screens for iOS. SwiftUI uses a declarative style where you describe how the UI should look, similar to Jetpack Compose in Android. UIkit, on the other... - Source: dev.to / over 2 years ago
All that's left is adding a little style. I won't claim to be a frontend engineer or a UI designer, so I just used UIKit to easily add modern-looking style to the HTML table and buttons. As mentioned throughout the article, the CSS classes and other small details are excluded since they are not directly relevant to the tutorial. See the full example on GitHub to try running it for yourself. - Source: dev.to / over 2 years ago
Can try UIKIT out if you're looking around, I've used it solely for some quick slider stuff in certain projects and use it fully in others. The docs are pretty good and they have a discord community that's fairly active. Source: about 3 years ago
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PDFShift - Convert any HTML documents to high-fidelity PDF using a single POST request
Semantic UI - A UI Component library implemented using a set of specifications designed around natural language
DocRaptor - As the only API powered by the Prince HTML-to-PDF engine, DocRaptor provides the best support for complex PDFs with powerful support for headers, page breaks, page numbers, flexbox, watermarks, accessible PDFs, and much more
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