sveltekit-superforms

Superforms 💥

Making SvelteKit forms a pleasure to use!

https://superforms.rocks/
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Feature list

• Server- and client-side validation with your favorite validation libraries, and more to come: 💥 Arktype 💥 class-validator 💥 Effect 💥 Joi 💥 Superstruct 💥 TypeBox 💥 Valibot 💥 VineJS 💥 Yup 💥 Zod 💥 or use JSON Schema directly.
• Seamless merging of PageData and ActionData - Forget about how to combine them, just focus on your form data, always strongly typed.
• Auto-centering and focusing on invalid form fields.
• Tainted form detection, prevents the user from losing data if navigating away from an unsaved form. Or use snapshots to save the form state.
• Automatically coerces FormData into correct types, including arrays and files.
• For advanced data structures, forget about the limitations of FormData - Post nested data structures like a RPC call.
• Generates default form values from many validation schemas.
• Handles multiple forms on the same page.
• Works both on the server and with single-page applications (SPA)!
• Convenient handling and validation of file uploads, both on server and client and even in nested data.
• Proxy objects for handling data conversions to string and back again.
• Realtime client-side validation for the best possible UX.
• Create loading spinners easily with three auto-updating timers, based on human perception research.
• Hook into a number of events for full control over the validation data and the ActionResult, with a possibility to cancel the update at every step.
• Complete customization with a huge list of options.
• No JavaScript required as default, but full support for progressive enhancement.
• Comes with a Super Debugging Svelte Component: SuperDebug.

Get started

Follow the Get started tutorial on the website to get a hands-on introduction to Superforms: https://superforms.rocks/get-started

You can also watch this excellent introduction video to see what's possible: https://www.youtube.com/watch?v=MiKzH3kcVfs

Help & support

• If you're using Superforms in non-profit circumstances, support is completely free; a star on Github is more than enough to show your appreciation. Join the #free-support channel on Discord and ask away!
• If you're making or aiming to make money on your project, a donation proportional to the current profit of the project or the company you work for, will give you a month of commercial support. Donate with one of the options on the website, then ask in the #commercial-support channel on Discord.

Contributing

General feedback, feature requests, bug reports, PR:s, are very welcome as a Github issue or on the Discord server!

Donating

If you appreciate the hard work behind Superforms, please support open source software with a donation.

Changelog

[2.26.1] - 2025-06-05

Removed

• The SuperDebug rune version broke Svelte 4 compatibility, so it has been removed until a solution can be figured out, hopefully very soon.

Fixed

• Zod 4 adapter now handles top-level discriminated unions.