--- description: Test a specific Worker version uploaded with wrangler versions upload. title: Version URLs image: https://developers.cloudflare.com/workers/versions-and-deployments/version-urls/og.png?v=b7754afab13e256b --- [Skip to content](#main-content) > Documentation Index > Fetch the complete documentation index at: https://developers.cloudflare.com/workers/llms.txt > Use this file to discover all available pages before exploring further. # Version URLs Last updated Sep 22, 2026|Copy as Markdown| [View as Markdown](https://developers.cloudflare.com/workers/versions-and-deployments/version-urls/index.md)| [Agent setup](https://developers.cloudflare.com/agent-setup/) Version URLs, previously called preview URLs, let you access an uploaded version of your Worker before deploying it to production. A Version URL uses that Worker version's existing configuration and resources instead of creating a separate environment. This is useful for testing a specific version directly. To test the version with your zone's performance or security settings, use [version overrides](https://developers.cloudflare.com/workers/versions-and-deployments/version-overrides/). For isolated branch or pull request testing, use [Previews](https://developers.cloudflare.com/workers/previews/). To compare Previews, Version URLs, and Wrangler environments, refer to [Compare workflows](https://developers.cloudflare.com/workers/previews/compare-workflows/). ## URL format Version URLs use this format: ```txt -..workers.dev ``` Aliased Version URLs use this format: ```txt -..workers.dev ``` ## Version URLs Every time you create a new [version](https://developers.cloudflare.com/workers/versions-and-deployments/#versions) of your Worker, Cloudflare can generate a unique Version URL for that version. New versions are created when you run: - [`wrangler deploy`](https://developers.cloudflare.com/workers/wrangler/commands/workers/#deploy) - [`wrangler versions upload`](https://developers.cloudflare.com/workers/wrangler/commands/workers/#versions-upload) - Dashboard code edits that save a new version If Version URLs are enabled, the URL is public and available after version creation. ### View Version URLs with Wrangler The [`wrangler versions upload`](https://developers.cloudflare.com/workers/wrangler/commands/workers/#versions-upload) command uploads a new version of your Worker and returns a Version URL for that version. ```sh npx wrangler versions upload ``` ### View Version URLs in the dashboard 1. In the Cloudflare dashboard, go to **Workers & Pages**. [Go to **Workers & Pages** ↗](https://dash.cloudflare.com/?to=/:account/workers-and-pages) 2. Select your Worker. 3. Go to **Deployments**. 4. Find the version you want to test. ## Aliased Version URLs Aliased Version URLs let you assign a readable alias to a specific Worker version. This can be useful when you want a stable URL for a manually uploaded version. Create an alias during version upload with `--preview-alias`: ```sh npx wrangler versions upload --preview-alias staging ``` The alias points at the version uploaded by that command: ```txt staging-..workers.dev ``` Aliases may only be created during version upload. ## Manage access to Version URLs When enabled, Version URLs are publicly available. To require visitors to sign in, use [Cloudflare Access](https://developers.cloudflare.com/workers/configuration/cloudflare-access/). Access can protect Version URLs for one Worker or every Worker in an account. You can also protect both production and version deployments. To use details about the signed-in user in your Worker, read the [user identity](https://developers.cloudflare.com/cloudflare-one/access-controls/applications/http-apps/authorization-cookie/application-token/#user-identity) from the validated JSON Web Token (JWT) or the `/cdn-cgi/access/get-identity` endpoint. ## Enable or disable Version URLs When no Version URL setting exists, Version URLs follow the same default as your `workers.dev` route: - If `workers_dev` is enabled, Version URLs are enabled by default. - If `workers_dev` is disabled, Version URLs are disabled by default. - Disabling Version URLs disables routing to Version URLs and aliased Version URLs. ### From the dashboard 1. In the Cloudflare dashboard, go to **Workers & Pages**. 2. Select your Worker. 3. Go to **Settings** > **Domains & Routes**. 4. Find **Version URLs**. 5. Select **Enable** or **Disable**. ### From Wrangler config To enable Version URLs, add `preview_urls` to your Wrangler config: Note The Wrangler configuration field is still named `preview_urls`. ```jsonc { "preview_urls": true } ``` ```toml preview_urls = true ``` To disable Version URLs: ```jsonc { "preview_urls": false } ``` ```toml preview_urls = false ``` If `preview_urls` is omitted, Wrangler does not change an existing Version URL setting. Set `preview_urls` explicitly to change it. ## Limits - Aliases may only be created during version upload. - Aliases must use only lowercase letters, numbers, and dashes. - Aliases must begin with a lowercase letter. - The alias and Worker name combined with a dash must not exceed 63 characters due to DNS label limits. - Only the 1000 most recently deployed aliases are retained. When a new alias is created beyond this limit, the least recently deployed alias is deleted. ## Limitations - Version URLs are not generated for Workers that implement a [Durable Object](https://developers.cloudflare.com/durable-objects/), including [Containers](https://developers.cloudflare.com/containers/) and [Sandbox](https://developers.cloudflare.com/sandbox/) Workers. For Containers testing options, refer to [Deploy Containers](https://developers.cloudflare.com/containers/guides/deploy/#before-production). - Version URLs are not generated for [Workers for Platforms](https://developers.cloudflare.com/cloudflare-for-platforms/workers-for-platforms/) [user Workers](https://developers.cloudflare.com/cloudflare-for-platforms/workers-for-platforms/how-workers-for-platforms-works/#user-workers). - You cannot configure Version URLs to run on a subdomain other than [`workers.dev`](https://developers.cloudflare.com/workers/configuration/routing/workers-dev/). - You cannot view logs for Version URLs with Workers Logs, Wrangler tail, or Logpush. Was this helpful? YesNo ## On this page [![](https://developers.cloudflare.com/_astro/logo.te5VL_aD.svg)Docs](https://developers.cloudflare.com/) ```json {"@context":"https://schema.org","@type":"TechArticle","@id":"https://developers.cloudflare.com/workers/versions-and-deployments/version-urls/#page","headline":"Version URLs","description":"Test a specific Worker version uploaded with wrangler versions upload.","url":"https://developers.cloudflare.com/workers/versions-and-deployments/version-urls/","inLanguage":"en","image":"https://developers.cloudflare.com/workers/versions-and-deployments/version-urls/og.png?v=b7754afab13e256b","dateModified":"2026-09-22","publisher":{"@type":"Organization","name":"Cloudflare","description":"One platform for your apps, agents, and workforce. 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