画像のリサイズと圧縮
完全無料・高速・プライバシー保護
Resize4U is a free browser-based tool that resizes, crops and compresses images without uploading them anywhere. When an application form rejects your photo for exceeding 50KB, a passport office demands exact 35×45mm dimensions, or a social platform blurs your upload, Resize4U fixes it in seconds — entirely on your device, keeping every photo completely private.
画像をアップロード
JPG, PNG, WebP, PDFに対応
ここに画像をドラッグ＆ドロップするか、クリックして選択
⚡ Quick Resize Presets
Resize4Uが選ばれる理由
100% プライバシー保護
すべての処理がブラウザ内で完結。画像がサーバーに送信されることは一切ありません。
超高速処理
アップロード待ち時間ゼロ。お使いの端末で瞬時に画像処理を行います。
完全無料
会員登録不要、課金なし、制限なし。いつでも気軽にご利用いただけます。
パスポート写真、履歴書、ビザ申請、試験フォーム、SNS投稿に最適
JPG, PNG, WebP, PDF対応 • 寸法指定または目標容量指定で圧縮 • 切り抜きと回転
Who is Resize4U for?
Millions of people hit an image problem every day that a normal editor can't solve. Here is how this tool helps each of them.
Students & job applicants
Exam boards, university admission portals and job sites enforce strict limits such as “photo between 20KB and 100KB”. Resize4U compresses to any exact KB target automatically, so your application never gets rejected for an oversized upload.
Passport & visa applicants
Official photo rules demand exact dimensions — 2×2 inches for US passports, 35×45mm across India, the UK and the Schengen area. Built-in country presets apply the correct size and 300 DPI print quality in one click.
Social media creators
Instagram posts, YouTube thumbnails, LinkedIn banners — every platform crops or blurs images uploaded at the wrong size. Pick a platform preset and your photo lands pixel-perfect the first time.
Website owners & bloggers
Oversized images are the number one cause of slow pages. Compress photos to a fraction of their original size before uploading, and your site loads faster, ranks better and keeps visitors engaged.
Anyone who values privacy
Your photos never leave your device. All processing happens inside your browser, which makes Resize4U safe for IDs, signatures, certificates and other sensitive documents that shouldn't be uploaded to a random website.
Unreliable or offline connections
Once the page has loaded, the tool keeps working without internet — useful while traveling, on metered mobile data, or whenever the connection drops mid-task.
How to resize an image in three steps
Select your photo
Drag and drop or click to browse. The image opens instantly on your own device — nothing is uploaded to any server.
Choose your goal
Set exact dimensions in pixels, cm or inches; pick a passport preset or a social platform; or enter a target file size in KB or MB. Crop, rotate and DPI are all adjustable.
Download instantly
Save the finished image as JPG, PNG or WebP in full quality, with no watermarks, no sign-up and no daily limits.
Guides & related tools
Task-specific versions of the tool plus in-depth guides with the exact sizes and requirements for each use case.
How Resize4U Compares
Unlike other online tools, Resize4U processes everything directly in your browser. Your photos never leave your device.
| Feature | Resize4UPrivacy First | iLoveIMG | TinyPNG | Canva |
|---|---|---|---|---|
| 100% Privacy (No Server Upload) | ✓ | ✗ | ✗ | ✗ |
| Works Completely Offline | ✓ | ✗ | ✗ | ✗ |
| No Registration Required | ✓ | ✓ | ✓ | ✗ |
| No File Size Limits (Client) | ✓ | ✗ | ✗ | ✗ |
| No Daily Limits | ✓ | ✗ | ✗ | ✗ |
| Compress to Exact File Size (KB) | ✓ | ✗ | ✗ | ✗ |
| DPI Control for Print | ✓ | ✗ | ✗ | ✗ |
| PDF Page Extraction | ✓ | ✓ | ✗ | ✗ |
| Crop & Rotate | ✓ | ✓ | ✗ | ✓ |
| Multiple Formats (JPG, PNG, WebP) | ✓ | ✓ | ✓ | ✓ |
| Always 100% Free | ✓ | ✗ | ✗ | ✗ |
Frequently Asked Questions
Everything you need to know about resizing and compressing images with Resize4U.
Is my data safe? Do you store my photos?▼
100% safe. Resize4U works entirely in your browser using client-side JavaScript. Your images are never uploaded to any server, stored in any database, or seen by anyone else. You can even use this tool offline without an internet connection.
What is the best format for resizing images?▼
For photos and complex images, JPEG offers the best balance of quality and small file size. For logos, graphics, and images with transparency, use PNG. WebP is the modern standard that gives superior compression for both photos and graphics with full transparency support.
How do I resize an image to a specific file size (e.g., under 50KB)?▼
Upload your image, enter your target file size in the "Target File Size" box (e.g., 50 KB), and click "Resize & Compress". Resize4U will automatically adjust the image quality and dimensions to meet your exact requirement.
What DPI should I use for printing vs web?▼
For web, social media, and screen display, 72 or 96 DPI is standard. For high-quality printing (passport photos, documents, photo prints), use 300 DPI. For standard document printing, 150 DPI is sufficient.
Can I resize photos for official documents like passports and visas?▼
Yes! Use our built-in presets for US Passport (2x2 inches / 51x51mm), EU Passport (35x45mm), Indian Passport, Schengen Visa, and more. All presets automatically apply the correct 300 DPI print standard.
Is there a limit on how many images I can resize?▼
No limits at all. You can resize as many images as you want, anytime, completely free without creating an account or subscribing.