Compress Image to 10 KB Online — Favicons, Avatars & Signatures

Shrink a small graphic or photo to under 10 KB in your browser — the size forum avatars, email signature logos, and favicon source images often need. Set the target and download.

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Use it right here — already set up for this task

画像圧縮

画像を目標サイズに圧縮

画像をアップロードし、希望の最大ファイルサイズを設定。無料、安全、ブラウザ内で動作。

画像をここにドラッグ&ドロップ

またはクリックして参照（PNG、JPG、WebP — 最大50MB）

共有

画像圧縮について

高度な画像圧縮ツールが、マルチパス適応圧縮で最適なファイルサイズ削減を実現。目標サイズを正確に設定し、画質とサイズの最適なバランスをエンジンが自動で見つけます。

機能：

  • 正確な最大ファイルサイズを設定（MBまたはKB）
  • スマートな画質検索によるマルチパス適応圧縮
  • PNG、JPG、WebP形式のサポート
  • 最大50MBの入力ファイルサイズ制限
  • 完全にブラウザ内で動作 — ファイルはデバイスから離れません
  • 登録不要で完全無料

参考資料・技術仕様

最終更新日: 2026-03-10

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画像リサイズ

SNSプリセット付きで任意のサイズにリサイズ。

画像形式変換

PNG、JPG、WebP形式間で変換。

一括写真編集

複数の写真を同じアスペクト比で一度にトリミング。

Open the full Image Compressor →

Why this matters

Forum profile avatars, email signature logos, and favicon source images are almost always small on screen (32–150 px), so they don't need much data to look sharp — but many old forum systems and signature platforms still enforce a hard 10 KB ceiling. At this size, honesty matters: a large, detailed photograph will not compress well at 10 KB and will show visible blocky artifacts, but a small logo, icon, or simple avatar with limited colors compresses cleanly because there's little detail to lose in the first place.

Step by step

  1. 1
    Open the Image Compressor
    The target is already set to 10 KB — drop in your avatar, logo, or icon source image.
  2. 2
    Compress
    The tool iterates quality in your browser to reach 10 KB or below.
  3. 3
    Check the preview closely
    At 10 KB, zoom in on the preview — simple graphics stay clean, but detailed photos will show visible artifacts.
  4. 4
    Simplify if it looks rough
    If quality is too degraded, crop tighter to just the subject or reduce the image's pixel dimensions first with the Image Resizer.
  5. 5
    Download and use
    Save the compressed file for your forum profile, signature, or favicon.

Frequently asked questions

Will 10 KB be enough for a real photo?

Usually not without visible quality loss. 10 KB is an aggressive target best suited to small logos, simple icons, and low-detail avatars — a detailed photo compressed this small will show blocky, washed-out artifacts.

What kinds of images compress best at 10 KB?

Flat-color logos, simple line-art avatars, and icons with fewer than a few dozen distinct colors. These have little fine detail, so aggressive compression stays visually clean.

Is my image uploaded to compress it this small?

No. Compression runs entirely in your browser regardless of the target size.

Why do old forums still cap avatars at 10 KB?

Many forum platforms (phpBB, vBulletin-era software) set these limits when server storage and bandwidth were expensive, and the defaults were never updated.

What if 10 KB is too small — can I use 20 KB instead?

Yes. The target field is fully editable; try 20 KB or 50 KB if your platform allows a larger limit.

Should I crop my photo before compressing to 10 KB?

Yes — cropping tightly to just the subject and reducing the pixel dimensions (e.g., to 150×150) before compressing gives noticeably better results than shrinking a full-size photo directly to 10 KB.

Try Image Compressor now
Free, private, no signup. Runs in your browser.
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Further reading

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