X (Twitter) で画像付きリンクを投稿する方法

Twitter Card META Tags

There are four current types of Twitter/X Cards: summary, summary_large_image, player, and app. The summary card shows a small thumbnail alongside your title and description; summary_large_image displays a large hero image above the text and is what most publishers use for link previews; player embeds inline audio or video; app links directly to an iOS/Android app listing. All META tag name attributes are prefixed with twitter:, and that hasn’t changed since the platform’s 2023 rebrand from Twitter to X — X still reads the same twitter:-prefixed tags.

Generic META Tags

META tags you would use in all card cases include:

• twitter:card – The type of card to be created: summary, summary_large_image, player, or app.
• twitter:url – The URL that should be used for the card. This will likely be the same URL as the page’s canonical link.
• twitter:title – The title as it should display in the Twitter Card.
• twitter:description – A 200 character summary of the content at the given URL.
• twitter:image – A representative image URL for the content. In many cases, simply providing your logo’s URL will be just fine, though a dedicated image sized around 1200×675 works best for the summary_large_image type.

Each of these items gets its own META tag, so the Twitter Card META tags for this page would look like this:

<meta name="twitter:card" content="summary_large_image">
<meta name="twitter:url" content="https://postrss.com">
<meta name="twitter:title" content="How To Post a Link on Twitter With Image">
<meta name="twitter:description" content="How To Post a Link on Twitter With Image.">
<meta name="twitter:image:src" content="https://postrss.com/wp-content/uploads/2014/01/mainslide1.jpg">

Source Code for WordPress

Source code for WordPress tags for Twitter for showing an image alongside links at posts:

<meta name="twitter:card" content="summary_large_image">
<meta name="twitter:url" content="<?php echo get_permalink($ID); ?>">
<meta name="twitter:title" content="<?php echo get_the_title($ID); ?>">
<meta name="twitter:description" content="<?php echo mb_substr($content,0,120); ?>">
<meta name="twitter:image:src" content="<?php $ID = $wp_query->post->ID; $image = wp_get_attachment_image_src( get_post_thumbnail_id( $ID ),'full'); echo $image[0]; ?>">

How to Test Your Card Preview

X retired its official Card Validator tool in 2022, so there’s no first-party way to preview a card without actually posting it. The most reliable check is to post the link on X yourself (a draft or unlisted post works if your account/workflow allows one) and look at the rendered preview directly. Several independent, free card-preview tools are also available online if you’d rather not post a test link publicly — search for “Twitter Card preview tool” and cross-check results against what your page’s own twitter: tags actually say, since third-party tools vary in how current their scraping is.

How This Applies to Automated Posting

When PostRSS automatically posts a new article from your RSS feed to X, the platform generates the link preview from whatever twitter: (or fallback Open Graph) tags exist on your page at the moment X’s crawler fetches it. Setting up correct twitter:card, twitter:title, and twitter:image tags on your website using the code above ensures your automated posts also get a proper image preview instead of a bare link.

Our RSS to Twitter page handles the X configuration end to end.

Common Reasons a Link Shows No Image on X

When a shared link appears as plain text or with the wrong picture, the cause is almost always on the page being linked, not on X. Check these points in order:

• The image URL is relative. Card and Open Graph images must use a full, absolute URL starting with https://, not a path like /images/photo.jpg.
• The image cannot be fetched. If the file is behind a login, blocked by robots rules or returns an error, the crawler has nothing to show.
• The tags are missing on that specific page. A theme may output card tags on the homepage but not on individual posts. View the source of the exact article URL, not just your homepage.
• The page has several conflicting image tags. Two different og:image values, for example from a theme and an SEO plugin at the same time, can lead to an unexpected picture.
• The old version is cached. As described below, card data is cached per URL, so a fix may not show until the cache refreshes.

Our guide on Open Graph tags and the wrong image goes deeper into the most frequent of these problems.

Getting the Right Image When Posting Automatically

With PostRSS, every new item in your feed becomes a post on X without anyone copying links by hand. PostRSS takes the picture from the feed item itself or from the Open Graph tags of the linked page, so the post carries your real featured image instead of a grey placeholder. That makes the tags described above doubly useful: they shape the preview X generates, and they give PostRSS a reliable image to work with.

The practical rule is simple: give every article a proper featured image, make sure your theme or SEO plugin outputs it as og:image and twitter:image, and use an image that still looks good when cropped to a wide format. If you want to decide exactly which picture is used, see our guide on controlling which image gets auto-posted from your RSS feed.

Frequently Asked Questions

Do I need both Open Graph and Twitter Card tags, or does one cover both?

X will fall back to your Open Graph tags (og:title, og:image, og:description) if dedicated twitter: tags aren’t present, so a page with solid OG tags alone will usually still get a reasonable preview. Adding twitter:card explicitly is what unlocks the larger summary_large_image layout specifically, though, so it’s worth setting even if your OG tags are already in place.

What image size should I use for summary_large_image?

X recommends an image around 1200×675 pixels (roughly a 1.91:1 aspect ratio), similar to Facebook’s Open Graph recommendation, so a single well-sized image can often serve both platforms.

Why is my Twitter Card still showing an old image after I updated it?

Like Facebook, X caches card data per URL for a period after it’s first scraped. Posting the link again, or waiting for the cache to expire, will typically pick up the updated image.

Does PostRSS post my article image to X automatically?

Yes. PostRSS takes the image from the feed item or from the Open Graph tags of the linked page, so each automated post carries the article’s real image.