画像を 400KB に圧縮（JPG）
画像を正確に 400KB に圧縮する無料オンラインツール。トリミング・リサイズ・自動削除に対応。
What is Zero-Upload?
All processing happens in your browser. No data is sent to our servers.
画像を 400KB に圧縮
- 画像をアップロード.
- 目標サイズ: 400KB.
- トリミング / 幅/高さ (任意).
- 圧縮 → 圧縮画像をダウンロード.
画像を 400KB に圧縮（JPG） – Precise & Private
Quickly compress images to exactly 400 KB (or nearby) while preserving clarity. Resize, crop, rotate and convert formats—fully in the browser with optional Zero‑Upload 100% privacy mode for sensitive content.
Adaptive Engine
Balances compression with sharpness in icons, UI elements and gradients.
Exact Targets
Hit strict limits (forms, portals, email) from 1 KB up to 2 MB.
Zero‑Upload Mode
Keep everything local—offline capable after initial load for maximum privacy.
Common Use Cases
- Job portal & application forms
- Email attachment limits
- E‑commerce product galleries
- Performance budgets (LCP-friendly)
- Blog / marketing hero images
- UI & dashboard assets
- Client previews & NDA media
- Documentation screenshots
FAQ
How do I get exactly 400 KB? ›
Use the target slider for 400 KB, optionally crop and reduce dimensions. The engine iteratively tunes quality.
Will the quality suffer? ›
Most images stay visually clean; extreme downscales or ultra-low targets may soften detail slightly.
Does Zero‑Upload affect results? ›
No quality loss—only processing location changes (local vs server). Privacy is maximized in Zero‑Upload.
Which format should I choose? ›
JPG for photos, WEBP for smallest modern size, PNG for transparency-critical graphics.
400KB — なぜ？
400KB は、アップロードの高速化、メール添付、サイズ制限のあるフォームに最適で、見た目の品質を維持します。
品質を保って 400KB を達成するコツ
Near-original clarity at ~2600–2800px; preserve textures and text readability.
人気の目標サイズ:
