ガイド
ブログのヘッダー画像とサムネイルに最適なサイズ
ヘッダーとサムネイルの寸法を揃えて、見た目と表示速度を両立する実践ガイドです。
画像サイズがバラバラだと記事一覧が乱れて見えます。標準サイズを決めると更新作業が速くなり品質も安定します。
Set one default size for blog headers
Choose a clear header width that matches your content area.
Using one repeatable header size keeps page rhythm and reduces manual tweaking.
Use smaller, consistent thumbnail ratios
Thumbnails should stay visually aligned in cards and sidebars.
Pick one ratio and keep it across category pages and home feeds.
- Use one shared thumbnail aspect ratio.
- Keep text overlays short and centered.
- Avoid mixing portrait and landscape thumbnails in one grid.
Resize for display width, then optimize file weight
Large source files do not improve quality if the rendered slot is smaller.
Resize first, then compress for faster loading and clearer workflow decisions.
Check desktop and mobile crop behavior
Header and thumbnail framing can shift on small screens.
Always preview your selected dimensions in both layouts before publishing.
Keep a mini size guide for your team
A simple shared document avoids repeated guessing.
Include approved widths, ratios, and file naming rules for faster uploads.
Use this when
- Setting image size rules for a blog template.
- Preparing featured images for new posts.
- Cleaning up inconsistent thumbnail layouts.
- Improving mobile readability and page speed.
Set standards and reuse them
Define a few reliable sizes, apply them consistently, and your blog visuals will look cleaner with less editing time.