Compress Image to 500 KB Online — Web Hero & Blog Images

Shrink a large hero image or blog featured photo to under 500 KB in your browser — a size that keeps pages fast without visibly sacrificing quality. Drop in the file and download the result.

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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

Hero images and blog featured photos are usually the single largest asset on a page, and an unoptimized one — 3–6 MB straight from a camera or stock photo library — can single-handedly tank a Core Web Vitals score and push Largest Contentful Paint past Google's recommended threshold. 500 KB is a practical sweet spot for large, wide images: still visually rich enough for a full-bleed banner, but small enough to load quickly on mobile connections. Compressing before upload is far faster than waiting for a CMS plugin to do it at publish time.

Step by step

  1. 1
    Open the Image Compressor
    The target is already set to 500 KB — drop in your hero or featured image.
  2. 2
    Compress
    The compressor iterates quality settings in your browser until the file is at or under 500 KB.
  3. 3
    Compare
    Check the preview at full width — 500 KB holds up well even for large banner images.
  4. 4
    Resize first if needed
    For very large source images, resize to your site's actual display width first with the Image Resizer, then compress.
  5. 5
    Download and publish
    Save the compressed image and upload it to your CMS or website.

Frequently asked questions

Why 500 KB for a hero image specifically?

It is large enough to preserve rich detail across a full-width banner while staying small enough to avoid hurting Largest Contentful Paint, a key Core Web Vitals metric.

Will 500 KB be enough for a full-width banner image?

Yes, for most photographic hero images at typical web display widths (1600–2000 px). Extremely detailed or high-contrast images may show very slight softening.

Is my image uploaded anywhere during compression?

No. All processing happens locally in your browser. Nothing is sent to a server until you manually publish it.

Should I resize before or after compressing?

Resize first if your source image is much larger than your site's display width — a 6000×4000 px photo shrunk to 1920 px wide will compress to 500 KB with noticeably better quality than compressing the full-resolution original.

What about WebP for even smaller hero images?

WebP typically shrinks another 25–35% versus JPG at the same visual quality. Convert with the Image Format Converter after compressing if your CMS supports WebP.

Does this help my page speed score?

Yes — oversized hero images are one of the most common causes of poor Largest Contentful Paint scores in Google PageSpeed Insights and Core Web Vitals.

Try Image Compressor now
Free, private, no signup. Runs in your browser.
Open Image Compressor →

Further reading

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