--- title: "2021.4 release notes" canonical_url: "https://www.nutrient.io/guides/web/release-notes/2021-4/" md_url: "https://www.nutrient.io/guides/web/release-notes/2021-4.md" last_updated: "2026-06-09T10:21:54.475Z" description: "Explore the new features of PSPDFKit 2021.4, including default JavaScript actions and improved TypeScript declarations for better integration and accuracy." --- # PSPDFKit 2021.4 migration guide for seamless updates In [PSPDFKit for Web 2021.4](https://www.nutrient.io/blog/pspdfkit-web-2021-4-undo-redo-document-editor-customization/), we changed the default value of [`NutrientViewer.Options.PDF_JAVASCRIPT`](https://www.nutrient.io/api/web/variables/NutrientViewer.Options.PDF_JAVASCRIPT.html) to `true`, so JavaScript actions will be enabled by default in Standalone mode (JavaScript actions aren’t supported in Server mode). If this setting affects your integration, you can restore the previous behavior by setting the option to `false` before calling [`NutrientViewer.load()`](https://www.nutrient.io/api/web/functions/NutrientViewer.load.html): ```js NutrientViewer.Options.PDF_JAVASCRIPT = false; NutrientViewer.load(configuration); ``` We completely changed the way we generate TypeScript declarations to make them more powerful and accurate. The internal API declarations are no longer exported, so if you were using those, it might lead to errors during the build step. This shouldn’t affect you if you weren’t using the types of internal APIs. If you still want to use internal types, most of them can be formed using the combination of `typeof` and [utility types](https://www.typescriptlang.org/docs/handbook/utility-types.html). Before: ```js import Instance from "pspdfkit/dist/types/typescript/Instance"; ``` After: ```js type Instance = InstanceType; ``` Some of the frequently used types are: ```js type Instance = InstanceType; type Rect = InstanceType; type Color = InstanceType; type Annotation = InstanceType; type TextSelection = InstanceType; type ToolbarItems = InstanceType["toolbarItems"]; type List = ReturnType; type Awaited = T extends PromiseLike? Awaited : T; type AnnotationsList = Awaited>; ``` We’re exploring ways to make this experience better in our upcoming releases. For a full list of changes, check out the [changelog](https://www.nutrient.io/guides/web/changelog.md#2021.4). ## Migrate PSPDFKit Server If you use PSPDFKit Server, make sure you read the [2021.4 server migration guide](https://www.nutrient.io/guides/product-archives-and-deprecated-solutions.md). --- ## Related pages - [1 0](/guides/web/release-notes/1-0.md) - [1 1](/guides/web/release-notes/1-1.md) - [1 10](/guides/web/release-notes/1-10.md) - [1 11](/guides/web/release-notes/1-11.md) - [1 12](/guides/web/release-notes/1-12.md) - [1 13 1](/guides/web/release-notes/1-13-1.md) - [1 13](/guides/web/release-notes/1-13.md) - [1 14](/guides/web/release-notes/1-14.md) - [1 15](/guides/web/release-notes/1-15.md) - [1 16](/guides/web/release-notes/1-16.md) - [1 17](/guides/web/release-notes/1-17.md) - [1 18](/guides/web/release-notes/1-18.md) - [1 2](/guides/web/release-notes/1-2.md) - [1 3](/guides/web/release-notes/1-3.md) - [1 4](/guides/web/release-notes/1-4.md) - [1 5](/guides/web/release-notes/1-5.md) - [1 6](/guides/web/release-notes/1-6.md) - [1 7](/guides/web/release-notes/1-7.md) - [1 8](/guides/web/release-notes/1-8.md) - [1 9](/guides/web/release-notes/1-9.md) - [2017 3](/guides/web/release-notes/2017-3.md) - [2017 6](/guides/web/release-notes/2017-6.md) - [Update your PSPDFKit for Web to version 2017.7](/guides/web/release-notes/2017-7.md) - [Upgrade annotations in PSPDFKit Web 2017.8](/guides/web/release-notes/2017-8.md) - [Explore new features in PSPDFKit for Web 2017.9](/guides/web/release-notes/2017-9.md) - [New features in the 2018.1 migration guide](/guides/web/release-notes/2018-1.md) - [PSPDFKit for Web 2018.2 migration insights](/guides/web/release-notes/2018-2.md) - [Discover the new features in PSPDFKit for Web 2018.3](/guides/web/release-notes/2018-3.md) - [Explore PSPDFKit for Web 2018.4 features](/guides/web/release-notes/2018-4.md) - [Explore new features in PSPDFKit 2018.5](/guides/web/release-notes/2018-5.md) - [Explore PSPDFKit for Web 2018.6 enhancements](/guides/web/release-notes/2018-6.md) - [Explore the new features in PSPDFKit 2018.7](/guides/web/release-notes/2018-7.md) - [Key updates in PSPDFKit for Web 2019.1](/guides/web/release-notes/2019-1.md) - [2019 2](/guides/web/release-notes/2019-2.md) - [PSPDFKit for Web 2019.3 migration highlights](/guides/web/release-notes/2019-3.md) - [Essential updates in PSPDFKit for Web 2019.4](/guides/web/release-notes/2019-4.md) - [PSPDFKit for Web 2019.5 migration insights](/guides/web/release-notes/2019-5.md) - [Key changes in PSPDFKit for Web 2020.1](/guides/web/release-notes/2020-1.md) - [Seamless migration to PSPDFKit for Web 2020.2](/guides/web/release-notes/2020-2.md) - [Upgrade to PSPDFKit Web 2020.3 seamlessly](/guides/web/release-notes/2020-3.md) - [PSPDFKit Web and Server 2020.4 migration update](/guides/web/release-notes/2020-4.md) - [Unified CRUD API enhancements for easy migration](/guides/web/release-notes/2020-5.md) - [PSPDFKit Web 2020.6 migration insights](/guides/web/release-notes/2020-6.md) - [Upgrade to PSPDFKit for Web 2021.1 with ease](/guides/web/release-notes/2021-1.md) - [Seamlessly migrate to PSPDFKit for Web 2021.2](/guides/web/release-notes/2021-2.md) - [2021 3](/guides/web/release-notes/2021-3.md) - [Migration guide for PSPDFKit 2021.5](/guides/web/release-notes/2021-5.md) - [2021 6](/guides/web/release-notes/2021-6.md) - [PSPDFKit 2022.1.1 migration changes](/guides/web/release-notes/2022-1.md) - [Enhancements in PSPDFKit for Web 2022.2](/guides/web/release-notes/2022-2.md) - [Explore the new features of PSPDFKit for Web 2022.3](/guides/web/release-notes/2022-3.md) - [PSPDFKit for Web 2022.4 migration overview](/guides/web/release-notes/2022-4.md) - [Key improvements in PSPDFKit for Web 2022.5](/guides/web/release-notes/2022-5.md) - [Discover the key updates in PSPDFKit for Web 2023.1](/guides/web/release-notes/2023-1.md) - [PSPDFKit 2023.2 migration and updates](/guides/web/release-notes/2023-2.md) - [Key updates in PSPDFKit for Web 2023.3](/guides/web/release-notes/2023-3.md) - [Explore key updates in PSPDFKit for Web 2023.4](/guides/web/release-notes/2023-4.md) - [Key updates in PSPDFKit for Web 2023.5](/guides/web/release-notes/2023-5.md) - [Essential Nutrient Web SDK 2024.1 migration tips](/guides/web/release-notes/2024-1.md) - [2024 2](/guides/web/release-notes/2024-2.md) - [2024 3](/guides/web/release-notes/2024-3.md) - [2024 4](/guides/web/release-notes/2024-4.md) - [2024 5](/guides/web/release-notes/2024-5.md) - [2024 7](/guides/web/release-notes/2024-7.md) - [2024 8](/guides/web/release-notes/2024-8.md) - [Upgrading Nutrient Web SDK](/guides/web/release-notes/upgrading.md)