These two get compared because both say "PDF SDK", but they solve different problems. Nutrient, the document platform formerly called PSPDFKit, is built around viewing a document faithfully and working on it as a PDF: annotations, form fields, signatures, redaction. Polotno SDK is a design editor you embed in your app, and it treats a PDF as a format it can read into editable layers and write back out. The question that decides it: do your users review documents, or redesign them? For review, pick Nutrient.
Pick the one that matches what your users do
Pick Nutrient if…
- Your users read and annotate documents. Highlights, comments, sticky notes, ink, and stamps are its core surface. Polotno has no annotation layer at all.
- You need AcroForm fields. Filling, validating, and flattening interactive forms is a first-class feature in Nutrient and unsupported in Polotno.
- You need digital signatures or permanent redaction. Digital signature workflows and true content removal are compliance features with real legal weight. Deleting an element in a design editor is not the same thing and should never be sold as if it were.
- You need native iOS and Android SDKs. Nutrient ships them. Polotno reaches iOS and Android through a WebView, and you build and maintain the bridge.
- Fidelity to the original file matters more than design freedom. A viewer renders the PDF as authored; a schema import reinterprets it.
Pick Polotno SDK if…
- Your users redesign the document instead of commenting on it. Import a PDF and get text as text, images as images, vectors as paths, all editable on a canvas.
- You generate designed documents from data. One template authored on the canvas plus a database row per document, rendered through the Cloud Render API or on your own servers. Nutrient merges data into HTML and Office templates. Polotno templates are designs authored on a canvas.
- PDF is one output among several. The same JSON schema exports PNG, JPEG, SVG, HTML, PPTX, GIF, and MP4 in the browser or on your own servers.
- Your users are not document specialists. The editing surface is a design canvas, closer to Canva than to Acrobat.
- You want print output. CMYK, spot colors, bleed, crop marks, and PDF/X-1a or PDF/X-4 come out of PDF export.
Viewing a document vs rewriting one
1. What happens when you open a PDF
Nutrient renders the document. The page you see is the page as authored, and anything you add sits in a separate annotation layer that a compliant viewer can show, hide, or export separately.
Polotno parses the document into typed elements with explicit coordinates, fonts, and colors, and from that point you are editing a design rather than a document. That is powerful when the goal is to change the content and lossy when the goal is to preserve the file exactly.
2. Who the editing surface is for
Nutrient's Web SDK UI is a document reader with tooling around it. Its content editor, a feature you add to your license, changes text inside the PDF, and its guides cover page work such as rotating, cropping, splitting, and merging. The result stays a PDF, which suits a user fixing a line in a contract. Its separate Document Authoring SDK is a Word-style DOCX editor, not a design canvas.
Polotno's UI is a canvas with layers, templates, and asset panels, and it assumes everything is movable. That suits a user rebuilding a flyer, and you export a new file at the end.
3. Output
Nutrient writes PDF back with annotations and form data intact. Polotno writes a new vector PDF, or any of the other supported formats, from the same schema. Interactive form fields and annotations do not carry through: form-field text and FreeText comments import as static design text, and no annotation layer survives.
4. Platform
Nutrient covers web, iOS, Android, React Native, Flutter, MAUI, and server SDKs for .NET, Java, Python, and Node.js. Polotno covers browsers, Node, and Electron for desktop, and reaches iOS, Android, React Native, and Flutter through a WebView rather than a native SDK. If your roadmap needs a native document SDK, that decides it on its own.
Feature comparison
| Capability | Polotno SDK | Nutrient |
|---|---|---|
| Opening a PDF | Imports it as editable design elements | Renders the file as authored |
| Changing page text | Text elements on a canvas, exported as a new file | Content editor inside the PDF, added to your license |
| Annotations | None | 17+ annotation types |
| AcroForms | None: field text imports as static text | Create, fill, validate, and flatten |
| Signatures | None | Electronic and digital |
| Redaction | None | Removes the underlying content |
| OCR | None | Offered as a component |
| PDF/A | Not in our docs | Converts and validates |
| Native mobile SDKs | None: WebView guides, and you maintain the bridge | iOS, Android, React Native, Flutter, MAUI |
| Design canvas for your users | Layers, templates, and asset panels | Not its focus |
| Export formats | PNG, JPEG, PDF, PPTX, GIF, MP4, plus SVG and HTML outside Cloud Render | PDF and Office formats, among others |
| CMYK, spot colors, bleed, crop marks, PDF/X-1a, PDF/X-4 | PDF/X is not listed on its SDK pages, so ask Nutrient | |
| Pricing model | Fixed license fee by custom quote, Cloud Render billed per use | Quote on capabilities, platforms, and deployment |
When Nutrient (PSPDFKit) is the right call
If the words "annotation", "form field", "signature", or "redaction" appear anywhere in your requirements, buy Nutrient. Polotno does none of those, and a design schema is the wrong base for them. A compliance workflow built on a visual stamp that any recipient can delete would be worse than no feature at all.
The same goes for high-fidelity viewing. If your product's promise is "this looks exactly like the file we were sent", a renderer is the right architecture and a parser is the wrong one. Nutrient also fits when your users fix text in a PDF and the file has to stay that PDF, and when your roadmap needs native mobile SDKs.
If your users design the documents instead, evaluate Polotno with the 30-day free trial, no credit card needed.
Where the naming gets confusing
PSPDFKit rebranded to Nutrient in October 2024, after acquiring ORPALIS, Aquaforest, Muhimbi, and Integrify. Both names refer to the same product, and a lot of search traffic still uses the old one, so you will see the two used interchangeably in comparisons, docs, and job listings. The web, Android, React Native, Flutter, Python, and Node.js packages carry the Nutrient name. The iOS Swift package and modules and the Android class names still say PSPDFKit.
FAQ
Can I use both?
Yes. Use Nutrient for the review workflow and Polotno for the authoring one. They share nothing, so the integration cost is two SDKs rather than one.
Which one handles scanned documents?
Nutrient, through its OCR component. Polotno imports a scan as images with no text to edit, and it drops an invisible OCR text layer on import, so running OCR first does not make the text editable.
