# JavaScript PDF fillable form library Nutrient Web SDK is a JavaScript library for filling, reading, creating, and editing PDF AcroForms. It offers developers an API for programmatic access to PDF form objects, as well as a beautiful UI for form filling. [Try for free](https://www.nutrient.io/sdk/web/getting-started.md) [Launch demo](https://www.nutrient.io/demo/forms) ## Limitations and known issues - **XFA forms** — XFA forms aren’t supported; convert them to AcroForms or flatten them to static PDFs. - **Dynamic behavior** — PDF form JavaScript, calculations, and custom actions are only partially supported; complex dynamic logic may need to be handled in your app. - **Field type restrictions** — Some field types or appearances (for example, rich text, barcode, or custom widgets) can render as plain text or be read-only in the web UI. For detailed workarounds, see [troubleshooting](https://www.nutrient.io/guides/web/troubleshoot.md). ## What are forms? The concept of forms in PDFs is similar to that of a form in the physical world. Forms allow a user to enter unique information into a preformatted page. As it’s an electronic format, PDF offers certain advantages to users — for example, the ability to edit entered information at a later date. [Learn more](https://www.nutrient.io/guides/web/forms/introduction-to-forms/what-are-forms.md) ## Essential guides --- **Supported form fields** Learn about the types of form fields supported by Nutrient [Read more](https://www.nutrient.io/guides/web/forms/introduction-to-forms.md) --- **Form data formats** Learn about using external files to manage form data [Read more](https://www.nutrient.io/guides/web/forms/introduction-to-forms/data-formats.md) --- **Flatten forms** How to flatten forms and burn them into a PDF [Read more](https://www.nutrient.io/guides/web/forms/flatten.md) ## Fill forms --- **Programmatic form fill** Learn the different approaches to programmatically filling form fields [Read more](https://www.nutrient.io/guides/web/forms/form-filling.md) --- **Fill form fields using the UI** Learn how end users can fill form fields with the built-in UI [Read more](https://www.nutrient.io/guides/web/forms/fill-form-fields/using-the-ui.md) --- **Attach a file to a PDF** How to attach a file to a PDF as an image annotation [Read more](https://www.nutrient.io/guides/web/forms/fill-form-fields/attach-a-file.md) --- **Add an image to a PDF** How to add an image to a PDF as an image annotation [Read more](https://www.nutrient.io/guides/web/forms/fill-form-fields/add-image.md) --- **Detect user form field input** How to subscribe to form events to detect form field input [Read more](https://www.nutrient.io/guides/web/forms/fill-form-fields/detect-user-input.md) --- **Form field permissions** How to configure form fill permissions [Read more](https://www.nutrient.io/guides/web/forms/fill-form-fields/permissions.md) --- **Fonts** How to dynamically load fonts when users enter text [Read more](https://www.nutrient.io/guides/web/forms/fill-form-fields/dynamic-font-loading.md) --- **Headless form fill** How to fill PDF forms without presenting the UI [Read more](https://www.nutrient.io/guides/web/forms/fill-form-fields/headless.md) ## Import form data --- **With Document Engine** How to import form data with Document Engine [Read more](https://www.nutrient.io/guides/web/forms/fill-form-fields/import-from-server-backed.md) --- **From Instant JSON** How to import form data from Instant JSON files [Read more](https://www.nutrient.io/guides/web/forms/fill-form-fields/import-from-instant-json.md) --- **From XFDF** How to import form data from XFDF files [Read more](https://www.nutrient.io/guides/web/forms/fill-form-fields/import-from-xfdf.md) --- **From a database** How to import form data from a database [Read more](https://www.nutrient.io/guides/web/forms/fill-form-fields/import-from-database.md) ## Form data — Read, extract, submit, or save --- **Extract form data** How to extract form field values present in a PDF document [Read more](https://www.nutrient.io/guides/web/forms/extract-form-data.md) --- **Read form fields** How to read all form objects present in a PDF document [Read more](https://www.nutrient.io/guides/web/forms/read-form-fields.md) --- **Submit or save form data using Document Engine** How to submit or save form data using Document Engine [Read more](https://www.nutrient.io/guides/web/forms/submit-or-save/to-server-backed.md) --- **Submit or save form data to an external source** How to submit or save form data to an external source [Read more](https://www.nutrient.io/guides/web/forms/form-submission.md) --- **Embed form data into a PDF** How to embed form data into a PDF document [Read more](https://www.nutrient.io/guides/web/forms/submit-or-save/embed-data-into-pdf.md) --- **Automatically save forms** How to configure the way forms are automatically saved [Read more](https://www.nutrient.io/guides/web/forms/submit-or-save/auto-save.md) --- **JavaScript validation** How to validate form field values using JavaScript [Read more](https://www.nutrient.io/guides/web/forms/javascript-validation.md) ## Create, edit, or remove forms --- **Browser form template builder** Canonical end-to-end browser form authoring: setup, editing, and exporting [Read more](https://www.nutrient.io/guides/web/forms/browser-form-template-builder.md) --- **Create a fillable form** How to programmatically create a fillable PDF form [Read more](https://www.nutrient.io/guides/web/forms/form-creation.md) --- **Add a signature field** How to add a signature form field to a PDF document [Read more](https://www.nutrient.io/guides/web/forms/create-edit-and-remove/add-signature-field.md) --- **Edit form fields** How to update a form field or widget annotation [Read more](https://www.nutrient.io/guides/web/forms/create-edit-and-remove/edit-fields.md) --- **Remove form fields** How to remove a form field from a PDF document [Read more](https://www.nutrient.io/guides/web/forms/create-edit-and-remove/remove-fields.md) --- **Form Creator** How to build an app where fields can be dragged and dropped onto a PDF [Read more](https://www.nutrient.io/guides/web/forms/create-edit-and-remove/built-in-ui.md) --- **Form field flags** How to configure form behavior and capabilities [Read more](https://www.nutrient.io/guides/web/forms/create-edit-and-remove/form-field-flags.md) --- **PDF actions support** Learn about the PDF actions supported by Nutrient [Read more](https://www.nutrient.io/guides/web/forms/pdf-actions-support.md) ## Framework support Nutrient Web SDK is compatible with any JavaScript framework, including React, Angular, Vue.js, Svelte, Blazor, Next.js, TypeScript, and Nuxt.js. It’s also compatible with ASP.NET, PHP, Laravel, and HTML5. **Call to Action** Start your free trial for unlimited access and expert support. [Learn More](https://www.nutrient.io/sdk/web/getting-started/other-frameworks/javascript.md) --- ## Related pages - [Extract data from PDF form fields using JavaScript](/guides/web/forms/extract-form-data.md) - [Flatten dynamic PDF forms using JavaScript](/guides/web/forms/flatten.md) - [Master PDF actions with JavaScript integration](/guides/web/forms/pdf-actions-support.md) - [Validate PDF forms using JavaScript](/guides/web/forms/javascript-validation.md) - [Read PDF form fields using JavaScript](/guides/web/forms/read-form-fields.md) ## Pages in this section - [Embed data into PDF forms using JavaScript](/guides/web/forms/submit-or-save/embed-data-into-pdf.md) - [Submit and save PDF forms using Document Engine](/guides/web/forms/submit-or-save/to-server-backed.md) - [Autosaving changes made to PDF forms](/guides/web/forms/submit-or-save/auto-save.md) - [Submit and save PDF forms to an external source](/guides/web/forms/form-submission.md) - [Adding a signature field to a PDF form](/guides/web/forms/create-edit-and-remove/add-signature-field.md) - [Build a browser form template builder](/guides/web/forms/browser-form-template-builder.md) - [JavaScript PDF Form Creator](/guides/web/forms/create-edit-and-remove/built-in-ui.md) - [Edit PDF form fields using JavaScript](/guides/web/forms/create-edit-and-remove/edit-fields.md) - [Create fillable PDF forms using JavaScript](/guides/web/forms/form-creation.md) - [Remove form fields from PDFs using JavaScript](/guides/web/forms/create-edit-and-remove/remove-fields.md) - [PDF form field flags](/guides/web/forms/create-edit-and-remove/form-field-flags.md) - [PDF form elements and data formats](/guides/web/forms/introduction-to-forms/data-formats.md) - [Supported PDF form fields](/guides/web/forms/introduction-to-forms.md) - [Understanding the benefits of PDF forms](/guides/web/forms/introduction-to-forms/what-are-forms.md) - [Adding an image to a PDF form using JavaScript](/guides/web/forms/fill-form-fields/add-image.md) - [Attach a file to a PDF form using JavaScript](/guides/web/forms/fill-form-fields/attach-a-file.md) - [Detecting user inputs in PDF forms](/guides/web/forms/fill-form-fields/detect-user-input.md) - [Dynamic font loading in PDF forms using Nutrient Web SDK](/guides/web/forms/fill-form-fields/dynamic-font-loading.md) - [Headless form fill](/guides/web/forms/fill-form-fields/headless.md) - [Import data into PDFs from a database](/guides/web/forms/fill-form-fields/import-from-database.md) - [Import data into PDF forms using Instant JSON](/guides/web/forms/fill-form-fields/import-from-instant-json.md) - [Import data into PDF form using Web SDK with Document Engine](/guides/web/forms/fill-form-fields/import-from-server-backed.md) - [Import data into PDF forms using XFDF](/guides/web/forms/fill-form-fields/import-from-xfdf.md) - [Customizing PDF form permissions](/guides/web/forms/fill-form-fields/permissions.md) - [Fill PDF forms programmatically using JavaScript](/guides/web/forms/form-filling.md) - [Fill PDF form fields using our JavaScript viewer UI](/guides/web/forms/fill-form-fields/using-the-ui.md)