These four vendors each grew out of a different product: Nutrient from a document viewer, Apryse from document processing, PDFMonkey from hosted document templates, and Polotno from a design editor that learned to read PDF. Which one you want depends on what your users do with the file. This page says where each vendor wins, including where we lose. For the open-source libraries, see JavaScript PDF libraries compared.
Four vendors, four different products
Nutrient – viewing, annotation, forms
Formerly PSPDFKit. It renders a document faithfully and lets your users layer things on top: highlights, comments, AcroForm fields, signatures, permanent redaction. It ships native iOS and Android SDKs as well. Buy it when your users review and mark up documents. See the Nutrient comparison.
Apryse – broad document processing
Formerly PDFTron. It covers more ground than anything else on this page: viewing, annotation, forms, OCR, classification, extraction, digital signatures, and PDF/A archiving, across .NET, Java, Python, C++, iOS, and Android. It sells that range in modules. See the Apryse comparison.
PDFMonkey – hosted templates
Your team builds a template in its dashboard, in a visual Builder or as HTML, CSS, and Liquid. Your code then sends JSON data and gets back a PDF or an image. It is a hosted service, and we found no embeddable editor in its docs. It fits when your team owns the templates and your documents run as flowing text. See the PDFMonkey comparison.
Polotno SDK – a design editor that reads PDF
A visual canvas over a JSON design schema, embedded in your product. It parses a PDF into editable text, images, tables, and vector paths, and writes vector PDF back out. Buy it when your users design documents inside your product. See the PDF SDK overview.
Ask who owns the layout
If a developer owns it and it never changes, a template service or a drawing library will do. If a document arrives from outside and its internal structure has to survive intact, you want a document library. If a marketer or an end user owns the layout and needs to change it without a deploy, you want an editor, and the editors differ. PDFMonkey's Builder lets your team assemble templates from blocks in its dashboard. Nutrient's Document Authoring and Apryse's DOCX editing are document editors. Polotno is a design canvas you embed in your product.
Then ask what happens to the file after that. Reviewing and signing a document is one product. Redesigning it is another.
Where Polotno is the wrong choice
- You need a viewer. A read-only canvas shows the imported design, not the file as authored, and there is no annotation layer.
- You need interactive forms. AcroForm text imports as static text, and the fields stop being fillable.
- You need OCR. A scan imports as images with nothing to edit as text, and an invisible OCR layer is dropped.
- You need redaction or digital signatures. Deleting an element is an edit, and we will not sell it as a compliance feature.
- The file has to stay the same PDF. Polotno rebuilds each page as a design and exports a new file, so bookmarks, form fields, and annotations do not carry over, and re-rendering does not compress it.
- You want a native library in Java, .NET, or Python. Polotno's packages are JavaScript and TypeScript. Those backends can still render through the Cloud Render API over REST, but they cannot run the SDK in-process.
- You need a native mobile SDK. Polotno reaches iOS and Android through a WebView, and you maintain the bridge.
- Your source is HTML. Polotno renders its own schema, not arbitrary markup.
Any one of those points you at Nutrient, Apryse, or PDFMonkey instead.
Where Polotno wins
- Your users redesign documents in your product. They work on the same canvas Polotno uses for images, text, and video.
- A non-developer needs a design canvas. They place everything freely, you store the template as JSON, and it changes without a release.
- Layout is positional. Certificates, tickets, labels, badges, business cards, and packaging get designed rather than typeset, and HTML pagination fights that.
- PDF is one output among several. Polotno SDK exports PNG, JPEG, PDF, SVG, HTML, PPTX, GIF, and MP4 in the browser or on your own servers. The Cloud Render API outputs PNG, JPEG, PDF, PPTX, GIF, and MP4.
- You need print-ready output. CMYK, spot colors, bleed, crop marks, and PDF/X-4 or PDF/X-1a.
If that describes your product, evaluate Polotno with the 30-day free trial, no credit card needed.
A shortlist in four questions
- Do your users read, annotate, or sign documents? → Nutrient, or Apryse for the wider platform
- Do you need OCR, extraction, or compliance archiving? → Apryse or Nutrient
- Does your team own the templates, for flowing documents with nothing to embed? → PDFMonkey
- Do your users design the document, or does a non-developer need a design canvas? → Polotno SDK
FAQ
Is there a single best PDF SDK?
No. The category bundles four unrelated jobs, and different companies lead each one.
Which one is cheapest?
That turns on your volume and on whether you also need an editor. PDFMonkey has a free tier and public plans. Nutrient quotes its SDKs on capabilities, platforms, and deployment, and Apryse describes its pricing as modular. Polotno charges a fixed license fee by custom quote, and the optional Cloud Render API bills per use.
Can I combine two?
Yes. Running a viewer SDK for review workflows alongside a design SDK for authoring is a workable split, because each one handles a job the other leaves out.
