Compress Image
JPEG Quality & Target Size
Shrink JPEG, PNG, or WebP file size in your browser. Set quality or a target size. Files never leave your device.
This conversion runs only in your browser — nothing is uploaded.
Drag & drop an image, or browse below
What is this tool?
A local image compressor. You pick JPEG quality and optionally a maximum size in kilobytes. The browser draws the image on a canvas and exports JPEG. Nothing is uploaded.
It does not convert HEIC (use HEIC to JPG first) and does not produce Base64 strings.
Common use cases
- Fit a photo under an email or form upload cap (for example 300–500 KB)
- Shrink a PNG screenshot that is mostly photographic content
- Batch a few web-hero images without opening desktop software
How to use
- Drop a JPEG, PNG, WebP, or GIF (GIF becomes a still JPEG).
- Set quality. Optionally enter a target size in KB.
- Check the before/after sizes, then Download JPG.
Examples
| Input | Notes |
|---|---|
| 4 MB phone JPEG, quality 75% | Typical web-share size drop with moderate artifacts. |
| PNG screenshot, target 400 KB | May still look blocky; screenshots compress poorly as JPEG. |
| Already-tiny 80 KB JPEG, quality 90% | Result can be larger — JPEG re-encode is not always smaller. |
| 15 MB+ image | Rejected; downscale in Photos first. |
Practical pitfalls
- Screenshots: UI chrome and text suffer as JPEG. This tool is aimed at photos.
- Transparency: alpha PNG becomes an opaque JPEG (usually black or white-filled by the canvas).
- Target size is best-effort; it cannot invent a 50 KB file from a 12 MP RAW-like JPEG without wrecking it.
References
이 도구는 무엇인가요?
A local image compressor. You pick JPEG quality and optionally a maximum size in kilobytes. The browser draws the image on a canvas and exports JPEG. Nothing is uploaded.
It does not convert HEIC (use HEIC to JPG first) and does not produce Base64 strings.
자주 쓰는 경우
- Fit a photo under an email or form upload cap (for example 300–500 KB)
- Shrink a PNG screenshot that is mostly photographic content
- Batch a few web-hero images without opening desktop software
사용 방법
- Drop a JPEG, PNG, WebP, or GIF (GIF becomes a still JPEG).
- Set quality. Optionally enter a target size in KB.
- Check the before/after sizes, then Download JPG.
예시
| Input | Notes |
|---|---|
| 4 MB phone JPEG, quality 75% | Typical web-share size drop with moderate artifacts. |
| PNG screenshot, target 400 KB | May still look blocky; screenshots compress poorly as JPEG. |
| Already-tiny 80 KB JPEG, quality 90% | Result can be larger — JPEG re-encode is not always smaller. |
| 15 MB+ image | Rejected; downscale in Photos first. |
실무에서 흔한 실수
- Screenshots: UI chrome and text suffer as JPEG. This tool is aimed at photos.
- Transparency: alpha PNG becomes an opaque JPEG (usually black or white-filled by the canvas).
- Target size is best-effort; it cannot invent a 50 KB file from a 12 MP RAW-like JPEG without wrecking it.
참고자료
このツールについて
A local image compressor. You pick JPEG quality and optionally a maximum size in kilobytes. The browser draws the image on a canvas and exports JPEG. Nothing is uploaded.
It does not convert HEIC (use HEIC to JPG first) and does not produce Base64 strings.
よくある用途
- Fit a photo under an email or form upload cap (for example 300–500 KB)
- Shrink a PNG screenshot that is mostly photographic content
- Batch a few web-hero images without opening desktop software
使い方
- Drop a JPEG, PNG, WebP, or GIF (GIF becomes a still JPEG).
- Set quality. Optionally enter a target size in KB.
- Check the before/after sizes, then Download JPG.
例
| Input | Notes |
|---|---|
| 4 MB phone JPEG, quality 75% | Typical web-share size drop with moderate artifacts. |
| PNG screenshot, target 400 KB | May still look blocky; screenshots compress poorly as JPEG. |
| Already-tiny 80 KB JPEG, quality 90% | Result can be larger — JPEG re-encode is not always smaller. |
| 15 MB+ image | Rejected; downscale in Photos first. |
実務での落とし穴
- Screenshots: UI chrome and text suffer as JPEG. This tool is aimed at photos.
- Transparency: alpha PNG becomes an opaque JPEG (usually black or white-filled by the canvas).
- Target size is best-effort; it cannot invent a 50 KB file from a 12 MP RAW-like JPEG without wrecking it.
参考資料
¿Qué es esta herramienta?
A local image compressor. You pick JPEG quality and optionally a maximum size in kilobytes. The browser draws the image on a canvas and exports JPEG. Nothing is uploaded.
It does not convert HEIC (use HEIC to JPG first) and does not produce Base64 strings.
Casos de uso comunes
- Fit a photo under an email or form upload cap (for example 300–500 KB)
- Shrink a PNG screenshot that is mostly photographic content
- Batch a few web-hero images without opening desktop software
Cómo usar
- Drop a JPEG, PNG, WebP, or GIF (GIF becomes a still JPEG).
- Set quality. Optionally enter a target size in KB.
- Check the before/after sizes, then Download JPG.
Ejemplos
| Input | Notes |
|---|---|
| 4 MB phone JPEG, quality 75% | Typical web-share size drop with moderate artifacts. |
| PNG screenshot, target 400 KB | May still look blocky; screenshots compress poorly as JPEG. |
| Already-tiny 80 KB JPEG, quality 90% | Result can be larger — JPEG re-encode is not always smaller. |
| 15 MB+ image | Rejected; downscale in Photos first. |
Errores prácticos
- Screenshots: UI chrome and text suffer as JPEG. This tool is aimed at photos.
- Transparency: alpha PNG becomes an opaque JPEG (usually black or white-filled by the canvas).
- Target size is best-effort; it cannot invent a 50 KB file from a 12 MP RAW-like JPEG without wrecking it.
Referencias
Qu'est-ce que cet outil ?
A local image compressor. You pick JPEG quality and optionally a maximum size in kilobytes. The browser draws the image on a canvas and exports JPEG. Nothing is uploaded.
It does not convert HEIC (use HEIC to JPG first) and does not produce Base64 strings.
Cas d'usage courants
- Fit a photo under an email or form upload cap (for example 300–500 KB)
- Shrink a PNG screenshot that is mostly photographic content
- Batch a few web-hero images without opening desktop software
Comment utiliser
- Drop a JPEG, PNG, WebP, or GIF (GIF becomes a still JPEG).
- Set quality. Optionally enter a target size in KB.
- Check the before/after sizes, then Download JPG.
Exemples
| Input | Notes |
|---|---|
| 4 MB phone JPEG, quality 75% | Typical web-share size drop with moderate artifacts. |
| PNG screenshot, target 400 KB | May still look blocky; screenshots compress poorly as JPEG. |
| Already-tiny 80 KB JPEG, quality 90% | Result can be larger — JPEG re-encode is not always smaller. |
| 15 MB+ image | Rejected; downscale in Photos first. |
Pièges courants
- Screenshots: UI chrome and text suffer as JPEG. This tool is aimed at photos.
- Transparency: alpha PNG becomes an opaque JPEG (usually black or white-filled by the canvas).
- Target size is best-effort; it cannot invent a 50 KB file from a 12 MP RAW-like JPEG without wrecking it.
Références
这个工具是什么？
A local image compressor. You pick JPEG quality and optionally a maximum size in kilobytes. The browser draws the image on a canvas and exports JPEG. Nothing is uploaded.
It does not convert HEIC (use HEIC to JPG first) and does not produce Base64 strings.
常见用途
- Fit a photo under an email or form upload cap (for example 300–500 KB)
- Shrink a PNG screenshot that is mostly photographic content
- Batch a few web-hero images without opening desktop software
如何使用
- Drop a JPEG, PNG, WebP, or GIF (GIF becomes a still JPEG).
- Set quality. Optionally enter a target size in KB.
- Check the before/after sizes, then Download JPG.
示例
| Input | Notes |
|---|---|
| 4 MB phone JPEG, quality 75% | Typical web-share size drop with moderate artifacts. |
| PNG screenshot, target 400 KB | May still look blocky; screenshots compress poorly as JPEG. |
| Already-tiny 80 KB JPEG, quality 90% | Result can be larger — JPEG re-encode is not always smaller. |
| 15 MB+ image | Rejected; downscale in Photos first. |
实践中的常见误区
- Screenshots: UI chrome and text suffer as JPEG. This tool is aimed at photos.
- Transparency: alpha PNG becomes an opaque JPEG (usually black or white-filled by the canvas).
- Target size is best-effort; it cannot invent a 50 KB file from a 12 MP RAW-like JPEG without wrecking it.
参考资料
這個工具是什麼？
A local image compressor. You pick JPEG quality and optionally a maximum size in kilobytes. The browser draws the image on a canvas and exports JPEG. Nothing is uploaded.
It does not convert HEIC (use HEIC to JPG first) and does not produce Base64 strings.
常見用途
- Fit a photo under an email or form upload cap (for example 300–500 KB)
- Shrink a PNG screenshot that is mostly photographic content
- Batch a few web-hero images without opening desktop software
如何使用
- Drop a JPEG, PNG, WebP, or GIF (GIF becomes a still JPEG).
- Set quality. Optionally enter a target size in KB.
- Check the before/after sizes, then Download JPG.
範例
| Input | Notes |
|---|---|
| 4 MB phone JPEG, quality 75% | Typical web-share size drop with moderate artifacts. |
| PNG screenshot, target 400 KB | May still look blocky; screenshots compress poorly as JPEG. |
| Already-tiny 80 KB JPEG, quality 90% | Result can be larger — JPEG re-encode is not always smaller. |
| 15 MB+ image | Rejected; downscale in Photos first. |
實務上常見陷阱
- Screenshots: UI chrome and text suffer as JPEG. This tool is aimed at photos.
- Transparency: alpha PNG becomes an opaque JPEG (usually black or white-filled by the canvas).
- Target size is best-effort; it cannot invent a 50 KB file from a 12 MP RAW-like JPEG without wrecking it.
參考資料
Last reviewed: 2026-08-30
Frequently asked questions
- Does this upload my photos?
- No. Re-encoding uses the canvas API in this tab. Close the page to drop the pixels from memory.
- Why is the result always JPEG?
- JPEG quality is the reliable browser knob for “make this smaller.” PNG stays lossless unless you re-encode; this tool converts to JPEG so quality/target-size controls actually shrink the file.
- Target size vs quality slider?
- Quality is a 10–95% JPEG factor. An optional target in KB binary-searches quality until the blob is under that size (or the minimum quality is reached). Huge photos may still miss a tiny target.
- Will faces and text stay sharp?
- Heavy compression adds block artifacts, especially on text and UI screenshots. Prefer PNG/WebP sources at a higher quality, or crop before compressing.