A few weeks ago we announced the first in a series of upgrades to Netlify’s form handling (beta), which allows you to add forms to your site without writing server-side code. Now, not only can you export form submissions to CSV, you can also delete submissions.
From the form detail page in the Netlify app, you can now select one or more form submissions, then click a button to delete them. (Be warned—the deletions are permanent!) You can also delete submissions programmatically using the Netlify API.