# What is a preview deployment?

> A preview deployment is a working copy of your site with one change, at its own link, to check before it goes live. What it is, with a real Kosuke example.

Source: https://learn.ynteractive.com/content/glossary/preview-deployment · Updated 2026-10-19 · Free from Stepthrough (https://learn.ynteractive.com)

[Web apps](https://learn.ynteractive.com/content/glossary#topic-web-apps) · [AI glossary](https://learn.ynteractive.com/content/glossary)

Quick answer

A preview deployment is a temporary, working copy of a website or app with one change applied, running at its own link. You and your client can click through it on a laptop or a phone before that change ever reaches the live site.

Last updated October 19, 2026

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Updated October 19, 2026 · By [Robert Breen](https://learn.ynteractive.com/content/about)

## Why it matters for a small business

For an agency, checking a change is often slower than making it. In the Kosuke lesson's example numbers, each website change takes about 1.5 hours of staging copies, screenshots and emails, which at 20 changes a month and $75 an hour is $2,250 of time. Screenshots show how a page looks, not whether a button works on a phone. A preview link replaces that round: the client clicks the real thing and approves what they tried.

It also protects the live site. Each preview runs on its own, so a broken change breaks only its own link while the real website keeps serving customers. The change goes live only after review, usually when someone merges its [pull request](https://learn.ynteractive.com/content/glossary/pull-request). That ordering is what stops the client from being the first person to find a bug.

## One website change, two ways to review it

| Step | Screenshots and email | Preview deployment |
| --- | --- | --- |
| Show the change | Staging copy, screenshots, an email | A link to the running site |
| Phone check | Often skipped | Responsive toggle in the Preview toolbar |
| Client sign-off | A reply to screenshots | The client clicks the button themselves |
| Go live | Someone pushes the change | The pull request is merged |

## In a real lesson: Preview Every Website Change Before Your Client Sees It using Kosuke

In [Preview Every Website Change Before Your Client Sees It using Kosuke](https://learn.ynteractive.com/content/kosuke-preview-website-changes-before-client-sees), Jordan Ellis at Harbor Lane Studio asks for a fee table on the Services page of Calder & Finch CPAs. When the agent finishes, the **Preview** on the right is the site running with the change. You click **Book a consultation**, see the contact form open with Business picked, then switch to phone size and catch the fee cards running off the screen.

After the fix and the QA run, you click **Share preview**, then **Create share link**. Whoever has the link can open the running site without a Kosuke account, and sees the site, not the chat or the code. The link has no password and no expiry, so the lesson says to send it only to the client and press **Revoke link** when you are done.

[Try this lesson free](https://learn.ynteractive.com/modules/kosuke-preview-changes) or [read the step-by-step guide](https://learn.ynteractive.com/content/kosuke-preview-website-changes-before-client-sees).

## Common confusions

### Preview deployment vs deployment

[Deployment](https://learn.ynteractive.com/content/glossary/web-app-deployment) puts the app live for everyone. A preview deployment is a private trial run of one change, at a separate link.

### Preview deployment vs a staging site

A staging site is one shared test copy that every change lands on. A preview deployment gives each change its own copy, so two changes never get mixed up in review.

## Tips

- Check the preview at phone size before you send it; most visitors are on phones.
- Click through it the way a client would, not just look at it.
- Revoke the share link once the client has approved.

## Related terms

[Deployment (publishing a web app)](https://learn.ynteractive.com/content/glossary/web-app-deployment) · [Pull request (PR)](https://learn.ynteractive.com/content/glossary/pull-request) · [Git branch](https://learn.ynteractive.com/content/glossary/git-branch) · [Sandbox environment](https://learn.ynteractive.com/content/glossary/sandbox-environment) · [Responsive design](https://learn.ynteractive.com/content/glossary/responsive-design) · [Shared link](https://learn.ynteractive.com/content/glossary/shared-link)

## More Web apps terms

[Request body (payload)](https://learn.ynteractive.com/content/glossary/request-body) · [Secrets and environment variables](https://learn.ynteractive.com/content/glossary/environment-variables) · [Submission states](https://learn.ynteractive.com/content/glossary/submission-states) · [Vibe coding](https://learn.ynteractive.com/content/glossary/vibe-coding)

## Where you use it: free lessons

- [Preview Every Website Change Before Your Client Sees It using Kosuke](https://learn.ynteractive.com/content/kosuke-preview-website-changes-before-client-sees) (Kosuke, 15 min)
- [Build a Landing Page with Lovable from One Prompt](https://learn.ynteractive.com/content/lovable-landing-page-from-one-prompt) (Lovable, 9 min)
- [Publish Your Lovable Site and Connect Your Own Domain](https://learn.ynteractive.com/content/lovable-custom-domain) (Lovable, 9 min)

## AI tools that use it

- [Kosuke](https://learn.ynteractive.com/content/ai-tools/coding-developer#tool-kosuke) ([free lesson](https://learn.ynteractive.com/content/kosuke-preview-website-changes-before-client-sees))

[More terms by tool](https://learn.ynteractive.com/content/glossary/ai-tool-terms)

## Frequently asked questions

**Is a preview deployment public?**

Only to people who have the link, unless the tool adds a password. Kosuke's share link has no password and no expiry, so treat it like a private document.

**Does a preview change my live website?**

No. The preview runs separately. The live site changes only when the reviewed change is merged and published.

**Do website builders have previews too?**

Yes. In the Lovable lessons the builder shows a preview of your site, and Publish is what puts it on a live lovable.app link.

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