Fabian Hiller
@fabianhiller.com
Creator of @valibot.dev, creator of Formisch, co-creator of https://standardschema.dev and engineer at https://usemotion.com
Thrilled to welcome LambdaTest as a new partner of Valibot! LambdaTest is a cloud-based testing platform that supports cross-browser testing on 3000+ browsers and real devices, with AI-powered features for test orchestration. Thank you for supporting our open source work!
November 13, 2025 at 3:05 PM
Thrilled to welcome LambdaTest as a new partner of Valibot! LambdaTest is a cloud-based testing platform that supports cross-browser testing on 3000+ browsers and real devices, with AI-powered features for test orchestration. Thank you for supporting our open source work!
Thank you for using Valibot 🙏
October 31, 2025 at 1:36 AM
Thank you for using Valibot 🙏
👀
📢Introducing ArkRegex📢
a drop in replacement for new RegExp() with types ⬇️
a drop in replacement for new RegExp() with types ⬇️
October 28, 2025 at 7:48 PM
👀
Reposted by Fabian Hiller
💡We can hide internals with ~ instead of _ for btter DX:
October 27, 2025 at 1:12 PM
💡We can hide internals with ~ instead of _ for btter DX:
I am excited to release the documentation for my new open-source project, Formisch.dev. It's time to rewrite your forms! 😉 Next, I will look into supporting @react.dev.
Formisch: The modular and type-safe form library for any framework
Formisch is a schema-based, headless form library for JS frameworks. It manages form state and validation. It is type-safe, fast by default and its bundle size is small due to its modular design.
Formisch.dev
October 27, 2025 at 3:14 AM
I am excited to release the documentation for my new open-source project, Formisch.dev. It's time to rewrite your forms! 😉 Next, I will look into supporting @react.dev.
Vitest 4 comes with a new `expect.schemaMatching` API that uses standardschema.dev behind the scenes. Now, you can use @valibot.dev, @zod.dev, @arktype.io, etc. to test your code! This is huge! 📈
Vitest 4 is out!
- Browser Mode is Stable
- Visual Regression Testing
- Improved Debugging
- Pool Stabilization
- New APIs
- Bug Fixes
Stay updated with our blog post:
vitest.dev/blog/vitest-4
- Browser Mode is Stable
- Visual Regression Testing
- Improved Debugging
- Pool Stabilization
- New APIs
- Bug Fixes
Stay updated with our blog post:
vitest.dev/blog/vitest-4
Announcing Vitest 4.0
Vitest 4.0 Release Announcement
vitest.dev
October 25, 2025 at 8:59 PM
Vitest 4 comes with a new `expect.schemaMatching` API that uses standardschema.dev behind the scenes. Now, you can use @valibot.dev, @zod.dev, @arktype.io, etc. to test your code! This is huge! 📈
Struggling with unknown data in TypeScript? @valibot.dev parses it effortlessly: validate & transform via pipes, grab detailed issues with safeParse (no throws!), and optimize perf with the abortEarly config.
October 15, 2025 at 2:43 PM
Struggling with unknown data in TypeScript? @valibot.dev parses it effortlessly: validate & transform via pipes, grab detailed issues with safeParse (no throws!), and optimize perf with the abortEarly config.
This message is for all @valibot.dev contributors. I recently added prompts to the Valibot repository that can be referenced when adding a new API reference to the website, for example, using an AI agent. github.com/fabian-hille...
valibot/prompts at main · fabian-hiller/valibot
The modular and type safe schema library for validating structural data 🤖 - fabian-hiller/valibot
github.com
October 15, 2025 at 1:22 AM
This message is for all @valibot.dev contributors. I recently added prompts to the Valibot repository that can be referenced when adding a new API reference to the website, for example, using an AI agent. github.com/fabian-hille...
@valibot.dev infers TS types + issues from your schemas! 🔥
No more boilerplate drudgery. Dive in: valibot.dev/guides/infer...
No more boilerplate drudgery. Dive in: valibot.dev/guides/infer...
October 14, 2025 at 3:03 PM
@valibot.dev infers TS types + issues from your schemas! 🔥
No more boilerplate drudgery. Dive in: valibot.dev/guides/infer...
No more boilerplate drudgery. Dive in: valibot.dev/guides/infer...
The docs for Formisch will probably be available in the next few days 🧱
October 13, 2025 at 12:40 AM
The docs for Formisch will probably be available in the next few days 🧱
Reposted by Fabian Hiller
@lgrammel https://x.com/lgrammel/status/1976644942425694511 #x-lgrammel
Latest AI SDK 6 beta supports the following validation libs:
Zod, Valibot, Arktype, Effect Schema
(Zod still needed for AI SDK-internal schemas)
Latest AI SDK 6 beta supports the following validation libs:
Zod, Valibot, Arktype, Effect Schema
(Zod still needed for AI SDK-internal schemas)
October 10, 2025 at 2:01 PM
@lgrammel https://x.com/lgrammel/status/1976644942425694511 #x-lgrammel
Latest AI SDK 6 beta supports the following validation libs:
Zod, Valibot, Arktype, Effect Schema
(Zod still needed for AI SDK-internal schemas)
Latest AI SDK 6 beta supports the following validation libs:
Zod, Valibot, Arktype, Effect Schema
(Zod still needed for AI SDK-internal schemas)
Hey everyone! Sorry for the instability of the @valibot.dev docs over the last two weeks. They should be working properly now. Our Vercel bill suddenly increased from a few dollars to over $300, so spent management disabled all services. I am in contact with @vercel.com.
October 9, 2025 at 1:09 PM
Hey everyone! Sorry for the instability of the @valibot.dev docs over the last two weeks. They should be working properly now. Our Vercel bill suddenly increased from a few dollars to over $300, so spent management disabled all services. I am in contact with @vercel.com.
What do you think about the new logo I designed for Formisch? 🧱
October 5, 2025 at 3:56 PM
What do you think about the new logo I designed for Formisch? 🧱
Thank you for your 8,000 stars on @github.com for @valibot.dev!
October 1, 2025 at 1:51 PM
Thank you for your 8,000 stars on @github.com for @valibot.dev!
This is maybe one of the best articles explaining the philosophy and design decisions of @valibot.dev. It's technical, yet still easy to read and understand! I recommend taking a look, especially if you are currently using other libraries, such as @zod.dev. dev.to/oluwawunmiad...
Understanding Valibot: How it Works and When to Use it
Discover how Valibot uses functional programming to deliver smaller bundles, faster validation, and better TypeScript support vs Zod and other libraries.
dev.to
September 29, 2025 at 7:43 PM
This is maybe one of the best articles explaining the philosophy and design decisions of @valibot.dev. It's technical, yet still easy to read and understand! I recommend taking a look, especially if you are currently using other libraries, such as @zod.dev. dev.to/oluwawunmiad...
We did it! Thank you! 🙏
September 24, 2025 at 1:09 PM
We did it! Thank you! 🙏
I guess I shipped on September 18th 🛳️
September 21, 2025 at 1:05 AM
I guess I shipped on September 18th 🛳️
Reposted by Fabian Hiller
Writing tests is hard, and I'm lazy. I'd rather write a few invariants, and let fast-check fuzz test the rest.
That's why I built @traversable/valibot-test.
Here it is in action:
That's why I built @traversable/valibot-test.
Here it is in action:
September 19, 2025 at 10:09 PM
Writing tests is hard, and I'm lazy. I'd rather write a few invariants, and let fast-check fuzz test the rest.
That's why I built @traversable/valibot-test.
Here it is in action:
That's why I built @traversable/valibot-test.
Here it is in action:
Reposted by Fabian Hiller
Join me and @fabianhiller.com live on This Week in Svelte to talk about Formisch! Live in 19 minutes or so!
youtube.com/live/E0xQXa4...
youtube.com/live/E0xQXa4...
This Week in Svelte, Ep. 117 — Changelog, Formisch
YouTube video by Svelte Society
youtube.com
September 19, 2025 at 3:11 PM
Join me and @fabianhiller.com live on This Week in Svelte to talk about Formisch! Live in 19 minutes or so!
youtube.com/live/E0xQXa4...
youtube.com/live/E0xQXa4...
Reposted by Fabian Hiller
In tomorrow's episode of This Week in Svelte @fabianhiller.com—creator of Valibot—will join the stream to talk about Formisch: www.youtube.com/live/E0xQXa4...
September 18, 2025 at 3:16 PM
In tomorrow's episode of This Week in Svelte @fabianhiller.com—creator of Valibot—will join the stream to talk about Formisch: www.youtube.com/live/E0xQXa4...
What are "pipelines" in @valibot.dev?
ℹ️ A pipeline is a left-to-right chain of schemas and actions
ℹ️ Each step gets the previous step’s output and can validate and transform
ℹ️ The final schema’s output type is the last step’s output type
ℹ️ A pipeline is a left-to-right chain of schemas and actions
ℹ️ Each step gets the previous step’s output and can validate and transform
ℹ️ The final schema’s output type is the last step’s output type
September 18, 2025 at 2:36 PM
What are "pipelines" in @valibot.dev?
ℹ️ A pipeline is a left-to-right chain of schemas and actions
ℹ️ Each step gets the previous step’s output and can validate and transform
ℹ️ The final schema’s output type is the last step’s output type
ℹ️ A pipeline is a left-to-right chain of schemas and actions
ℹ️ Each step gets the previous step’s output and can validate and transform
ℹ️ The final schema’s output type is the last step’s output type
Thank you for 2,003,706 downloads in the last 7 days 🙏
September 17, 2025 at 3:06 PM
Thank you for 2,003,706 downloads in the last 7 days 🙏