FormBoundary — Form Validation Checker icon

FormBoundary — Form Validation Checker

by kmin · Developer Tools
Manifest V3 in_app
View in Chrome Web Store Data as of 16 Oct 2026

Check whether HTML form constraints match client-side validation after input, change, and blur.

Users
4
0 in 30 days
Rating
0.0 / 5
unchanged in 30 days
Ratings
0
0 in 30 days
Store rank
#276K
#229K among extensions
Version
0.2.1
updated 8 Aug 2026

Users

monthly, 2 months
025Aug 2026Oct 2026Oct 2026
Latest, 16 Oct 2026: 4 usersMove the mouse over the chart for any month

Ratings count

monthly, 2 months
001Aug 2026Oct 2026Oct 2026
Latest, 16 Oct 2026: 0 ratingsMove the mouse over the chart for any month

The Chrome Web Store rounds user counts down to the leading digit, so the user line moves in steps. The ratings count is exact and is the better signal of real adoption.

About FormBoundary — Form Validation Checker

FormBoundary is a focused, local checker for native web-form validation. It reads validation constraints that are visible in native HTML fields, generates representative boundary values, enters one value at a time, triggers input, change, and blur events, and reports when the field's final client-side validity disagrees with the expected result derived from those constraints. Example issues it can expose: • A value allowed by HTML is rejected by JavaScript through the browser validation API. • A value outside the scanned HTML range is accepted after page logic changes or clears the constraint. • A length, range, step, required, pattern, email, date, or option case behaves differently from its declared constraint. Free includes field scanning, generated cases, single-case execution, and consistency results. Pro adds sequential batch runs, result summaries, local saved plans, reruns, and JSON/CSV reports. To request a Pro activation code, contact wkm534470831@gmail.com or WeChat kmin_w. Activation is handled manually. No price, payment link, or purchase button is shown in the extension. Privacy and safety: • Runs locally in your browser • No account or developer-operated server • No analytics or ads • Never submits forms automatically • Skips password and likely sensitive fields • Uses activeTab only after your action Important limitations: • It checks visible native input, textarea, and select fields only. • It does not click Submit or test validation that runs only in a submit handler. • It does not test server/API validation or hidden business rules. • It cannot reliably detect a visual error message unless the page also exposes the result through the field's browser validity state. • It does not support every custom component, Shadow DOM, or iframe. FormBoundary is not a complete end-to-end testing tool. It is a quick consistency check for a narrow class of client-side form-validation mistakes.

Growth

WindowUsersChangeRatingsRating
7 days−1−20.0%00.00
30 days0+0.0%00.00

Version history

1 versions recorded
0.2.18 Aug 2026

Details

Category
Developer Tools
First seen
8 Aug 2026
Size
47 KB
Languages
en
Pricing
in_app
Privacy policy
github.com
Support
github.com
Extension ID
npooffodjkomebcaaalmcipmmdghhdnm

Permissions and risk

Minimal riskimpact 0, likelihood 3
Permissions
activeTabscriptingstorage

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