画像リサイズツール
ブラウザ内で画像サイズを変更。幅と高さを設定し、縦横比を固定してダウンロードできます。
Design 2560 × 1440 YouTube channel art in your browser with 15 templates, text, logos, shapes, gradients, layers and a safe-area guide, then export PNG or JPG under 6 MB.
このツールはブラウザ内で動作します。入力内容、ファイル、生成した値はこの端末に残ります。お気に入りと最近使ったツールを利用する場合も、ローカルストレージに保存されるのはツール名だけで、パスワード、文書、QR コードの内容は保存されません。 詳しくはプライバシーポリシーをご覧ください。
このツールの詳しい解説(使い方、例、よくある質問)は、現在英語のみでご用意しています。
This YouTube banner maker builds channel art at the full 2560 × 1440 pixel size inside your browser. Start from one of 15 original templates or a blank colour, then add text, photos, a logo, rectangles, circles and gradients. A dashed 1546 × 423 guide marks the strip that stays visible on phones, desktops and TVs. The guide helps you place names and slogans, and it is never drawn into the downloaded file. Nothing you upload leaves your device, because the editing and the export both run on a canvas element in the page.
Load Neon Arena, change the title to the channel name, change the tagline to the real stream days, and drag a transparent PNG logo to the left side of the safe area. The neon slash sits behind the text, so the name stays readable on a phone.
Start from Minimal Mono, press Image and choose a landscape photo. The photo is scaled to fit the full canvas. Use the down arrow in the Layers list to send it below the title, then lower its opacity so the words stand out.
A detailed photo exported as PNG can be larger than 6 MB at this size. When that happens the tool switches to JPG and lowers the quality step by step until the file fits, and the status line tells you which format and size you received.
The editor keeps your design as a list of layers drawn in order from bottom to top over a background fill. Every change, from a colour pick to a drag, produces a new version of that list, and up to 60 versions are kept so undo and redo can step through them. The preview canvas is always the true 2560 × 1440 size and is only scaled down with CSS, so what you see is what you export.
The safe area is centred on the canvas. Its left edge sits at (2560 − 1546) ÷ 2 = 507 pixels and its top edge at (1440 − 423) ÷ 2 = 508.5 pixels. Anything inside that box is visible on every device class YouTube supports. Wider strips appear on desktop and the whole image can appear on TV, so the outer area is a good place for texture, colour and photo detail rather than words.
Pointer positions are converted from screen pixels to canvas pixels by dividing by the displayed width and height and multiplying by 2560 and 1440. That keeps dragging accurate at any zoom level and on any screen. Gradients use the CSS angle convention, where 90 degrees runs left to right and 180 degrees runs top to bottom.
Text wraps inside each text box. The tool measures each word with the browser's font metrics and starts a new line when the next word would pass the box width. Line spacing is 1.2 times the font size.
On export the design is drawn again on a fresh canvas with no guide, no selection outline and no resize handle. A PNG is tried first when you choose PNG. If it is over 6 MB, or if you chose JPG, the tool encodes JPG at quality 0.92 and steps down through 0.85, 0.75, 0.65 and 0.5 until the file is 6 MB or smaller.
On a phone the banner is shown as a thin strip, roughly the safe area, so a name in large letters reads better than a sentence. A tagline of four to six words is usually enough. High contrast between text and background matters more than font choice at that size.
Logos with transparent backgrounds look cleaner than logos on a white box. If your logo is a JPG with a white background, place it on a light area of the design or redraw it as a PNG first. The Logo button scales any image to fit a 300-pixel square and places it near the left edge of the safe area.
Pick one strong background colour or a two-colour gradient and one accent colour, then use the accent sparingly for a bar, a ring or a single word. Light text on a dark background reads well at small sizes, and so does near-black text on a pale background. Mid-tone text on a mid-tone background is the combination most likely to disappear on a phone.
Bold or semibold weights hold up better than regular weight when the banner is shrunk. The Condensed option fits longer names on one line, and the Serif option suits cooking, travel and education channels that want a calmer look.
Images are read with the browser's FileReader and kept in memory as data URLs. They are not sent to Tools Star Hub or any other server. Closing or reloading the tab clears the design, so download a copy before you leave.
The editor has no rotation, crop, filters, custom font upload or saved projects, and the design is lost when the tab closes. Browser fonts differ slightly between systems, so text can wrap a little differently on another computer. Very large photos can make older phones slow. YouTube can change its banner sizes or file limits, so confirm the current figures in YouTube Help before you upload.
See the disclaimer for what these tools do not cover.
ブラウザ内で画像サイズを変更。幅と高さを設定し、縦横比を固定してダウンロードできます。
JPG・PNG・WebP画像をアップロードせずにブラウザ内で圧縮します。
JPG・PNG・WebP上で枠をドラッグし、枠内のピクセルをダウンロードします。自由、1:1、4:3、16:9に対応。回転やフィルターはありません。
線形・放射・円錐のCSSグラデーションやグラデーション文字を作り、CSSまたはHTMLをコピーできます。
ブラウザのカラーピッカーで色を選び、HEX・RGB・HSLの値をコピーできます。
JPGをPNGに、PNGをJPGにブラウザ内で変換します。透明部分には背景色を指定できます。