How to use Twitter cards

When someone pastes your launch URL on X, the preview they see comes from your page, not from the tweet you wish they had written. A broken image or a stale title can make a good changelog look unfinished. This page follows X's current official Cards sources and does not invent field names the live docs no longer list.

What is a Twitter Card?

It is the title, description, and image X can show when someone posts a link to your site. A card is not an embed of an X post, and it is not a paid Ads API card. On 10 November 2026 (PT), the official Cards source on docs.x.com is the Developer Policy "X Cards" section, not a markup guide.

A 2 November 2026 Wayback snapshot of the X Developer Policy, captured at 10:20 PM PT, includes an "X Cards" section. In the text fetched, that section does not publish a list of website preview types such as a summary card. The one card type it names is an App Card. Older markup-guide URLs have returned 404, and this guide does not paste field names from 2015 blogs as if they were current official types.

Why should a launch page or changelog have a correct card?

Those are the URLs people actually share after you announce something. If the preview still shows an old feature name, a default CMS image, or no image at all, the share undersells the work. Fixing the card helps every future share of that URL, including ones you did not write.

Evenpost is an app for X (Twitter) for solo founders. You and your agent draft, you approve each post in the Evenpost app, and it posts with natural spacing, or right away if you choose Post now. Updates: @evenpost. Approval still happens in the app. The card itself is configured on your site, not in the composer.

Which card type should you use for a product page?

Do not add card types from memory. On 10 November 2026 (PT), docs.x.com had no list of summary or large-image tags as current official types. The Developer Policy "X Cards" section mentions App Cards and requires HTTPS assets, sensitive-media labeling, and no third-party sponsored content without approval. This page quotes only types official docs still name.

The 2 November 2026 policy snapshot says you must develop your Card to render across platforms where Cards are displayed, mark a post as sensitive if you plan to display such media in a Card, and use HTTPS for hosting all assets in the Card. Audio and video should include stop or pause controls, and video that plays automatically should default to sound off. You may not place third-party sponsored content in a Card without X's approval, attach monetary incentives, or include misleading content. It also says:

You may only attach an App Card to a Post when someone is explicitly promoting or referring to the app in the Post.

If you are sharing a launch page or changelog, inspect the unfurl you actually get. Do not copy a summary or summary_large_image tag out of an old blog and call it current official documentation. Those names are not listed as official types in the policy snapshot quoted here.

Ads API cards on docs.x.com are a different product: promoted or advertiser cards. Do not treat those types as website preview tags. The docs.x.com webpage-properties page covers widget meta tags such as twitter:widgets and twitter:dnt. It is not a Cards markup guide.

How do you check the preview before people share the link?

Paste the URL into the X composer and look at the unfurl. That check still works even if markup docs are gone. On 10 November 2026 (PT), cards-dev.x.com/validator redirected to an X login. Do not assume a logged-out validator still works. If the preview is stale, say only what official docs or a dated test show about refresh.

Link fees, when they apply, are a separate question. See the live answer Does a link make an X post cost more?. No prices are listed, and no ranking penalty is assumed.

Writing the launch post that may include the URL is also a different job, owned by a planned launch guide which is a separate guide.

How is a card different from embedding a post?

A card previews your URL when it is shared on X. An embed shows an X post on your site. Launch pages often need both, but they are configured in different places. The embed page owns snippets and CMS blocks. This page owns preview checks and the official Cards rules.

The embed guide is planned.

Check the composer preview of your launch URL before you ask other people to share it, and fix the card tags if the image or title is still last month's feature.

FAQ

Do I need a developer account to use Twitter cards?

The official source this page quotes is the Developer Policy "X Cards" section, which is written for people building on X's developer platform. A public launch page can still unfurl in the composer without this page inventing an account requirement. Confirm current docs if you are implementing an App Card or another official type.

Can I use Open Graph tags instead of twitter: tags?

This guide does not invent a substitution rule. The policy snapshot quoted here does not publish a current website-preview markup list. Inspect the composer unfurl of your actual URL, and quote only field names you can see or that official docs still list.

Why is my card image not updating?

This guide does not invent a cache-refresh step. On 10 November 2026 the old validator URL redirected to login, so do not assume a logged-out validator will clear a stale image. Recheck the live page's tags and the composer unfurl, and only describe a refresh method official docs or a dated test show.

What size should the card image be?

Official docs quoted here do not list image dimensions for a website preview card. This guide does not invent a size. Use the composer unfurl of your URL to see what X actually shows, and re-read current official Cards sources on publish day.

Is the old cards-dev.twitter.com validator still alive?

On 10 November 2026, 10:40 AM PT, https://cards-dev.x.com/validator redirected to an X login page. Do not assume a logged-out validator still works. The composer unfurl remains the check this page recommends.