Resize Image to 50KB Online
Compress photos, scans and screenshots to 50 KB in your browser. The result panel reports the true output size and resolution for every file, including the ones that miss.
画像をここにドロップまたはクリックしてアップロード
JPG, PNG, WEBP, BMPに対応
What 50 Kilobytes Buys You
50 KB is 51,200 bytes, two and a half times the budget of the 20 KB page, and that extra room changes what is realistic. A photograph costing roughly a third of a byte per pixel fits around 150,000 pixels at 50 KB, which is about 500 by 340 - a picture you can actually look at rather than a thumbnail. Scanned paper does much better again. A typed or handwritten document is mostly a single flat background colour with thin dark strokes on it, and JPEG spends almost no bytes on flat regions, so an A4 scan often survives at 1000 pixels wide or more inside the same 50 KB. That gap between photographs and documents is the single most useful thing to understand about this target, because it explains why two files of identical original size come back at wildly different resolutions. The tool does not assume which kind of image you gave it. It encodes once, measures the real byte count and pixel count of the output, derives the bytes per pixel that this particular image costs, and solves for the pixel count the budget allows. A detailed forest photograph and a flat scanned form will therefore be handled completely differently without you selecting anything. Bounds apply in both directions: JPEG quality never falls below about 0.54, the long side never goes under 96 pixels, and at most five encodes run per file. If 50 KB is still out of reach after that, the page reports the closest size it achieved and names which limit stopped it. EXIF and GPS tags are removed during encoding, both because they waste bytes and because a scanned document does not need to carry the coordinates of the desk it was photographed on.
Where the 50KB Limit Comes From
50 KB is the most common ceiling on recruitment and admission portals across South and Southeast Asia. Application systems that cap the candidate photograph at 20 KB frequently allow 50 KB for the scanned signature page, the identity document or the qualification certificate, and applicants who compress everything to the strictest number end up with unreadable certificates for no reason. Outside those portals, 50 KB is where email signature graphics, forum avatars, marketplace listing thumbnails and message board attachments tend to sit, and it is a common cap on legacy content management systems whose upload handler was configured before smartphone cameras existed. It is also a practical target for anyone sending images over a metered or unreliable connection. A gallery of twenty product photos at 50 KB each moves in a second on a connection where the same gallery at 2 MB each would time out. The reason to use a page pinned to one number, rather than a quality slider, is that the number is what you were given - a form told you 50 KB, and you need to know whether your file cleared it, not what quality percentage produced it. The failure mode a slider cannot protect you from is the one that costs a day: you settle on a quality setting that looks acceptable, upload the file, and discover at the portal that it is 53 KB. Fixing the target and reporting the measured result removes that round trip entirely.
How to Compress an Image to 50KB
Work from the original scan or photo, and decide before you start whether resolution or fidelity matters more for this particular file - a certificate needs to stay readable, a profile photo does not.
Upload your files. JPG, PNG, WebP and BMP are accepted, and you can queue a batch
Keep the output on JPEG for photos and scans; choose WebP only if you know the destination accepts it
Click Apply, then read each result row for its byte size and its output resolution
For a document that came back too small to read, crop away the blank margins first and run it again - fewer pixels of paper means more pixels of text inside the same 50 KB
Frequently Asked Questions
その他の画像ツール
画像編集のニーズに応える他の強力なツールをご覧ください
画像圧縮
サイズ縮小
画像切り抜き
領域を切り取る
形式変換
形式を変更
フォトエディター
写真を編集
画像回転
画像を回転
画像反転
水平/垂直反転
透かしを追加
透かし
枠線追加
画像枠線を追加
角丸
角丸を追加
フィルター
明るさ/コントラスト
顔をぼかす
顔を隠す
モザイク
領域をぼかす
背景削除
背景を削除
画質向上
AI拡大
テキスト追加
画像にテキストを追加
コラージュ
複数の画像を結合
HTMLから画像
Webを画像に
GIF からシーケンス
フレーム抽出
画像の余白を削除
空白の縁を削除
画像を一括リネーム
ファイル名を安全に一括変更
円形切り抜き
画像を円形に切り抜き
白黒
画像をグレースケールに変換
画像分割
画像をグリッドに分割
画像結合
画像を1つに結合
DPI変更
画像のDPIメタデータを設定
画像→Base64
画像をBase64にエンコード
画像をPDFに結合
複数の画像を1つのPDFにまとめる
HEIC→JPG
iPhoneのHEIC写真をJPGに変換
EXIF除去ツール
GPS位置情報を含む写真の隠しメタデータを表示・除去
ファビコン ジェネレーター
完全なアイコンセットとHTML
カラーパレット
画像から色を抽出
Base64 to Image
Decode Base64 back to an image
HEIC to PNG
Convert iPhone HEIC photos to lossless PNG
Text Behind Image
Put text behind the subject of a photo, entirely in your browser
Color Picker
Get the HEX, RGB and HSL of any pixel
Signature Maker
Draw a signature and download it as a transparent PNG
Signature Background Remover
Ink from paper, on transparency
Transparent Background Maker
Make a background transparent