iToolsPro
⌘ K

JPG Quality Adjust

Freely adjust JPG compression quality with live size comparison and one-click export

Upload & quality

Click or drag an image here

PNG / JPG / WebP supported; exports as JPG

80%
Original size-
Compressed size-
Size change-
Tip: runs locally, nothing is uploaded. Lower quality means smaller files but more visible loss.
Preview compare
Original
Compressed
Drag the slider to preview compression live - watch edge details for artifacts.
Quality · Size · Save

Quality vs size, find the sweet spot

Drag a slider to freely adjust JPG compression quality, compare size and savings in real time, and find the best balance between quality and file size. All local, nothing uploaded.

100% local · nothing uploaded

Features

Fine control
A 1-100 quality slider with precise percentage control over JPG compression.
Live compare
Side-by-side preview of original vs compressed, with size change and savings rate in real time.
Local & private
All compression runs in your browser - images never leave your device, safe for private photos.

Use cases

🌐 Web images ✉️ Email attachments 💬 Social sharing 🗄 Storage slim-down

JPG质量调整指南JPG Quality Adjust Guide

了解质量参数、体积权衡与常见问题。Quality parameters, size trade-offs, and answers to common questions.

功能说明What It Does

JPG质量调整工具通过 1-100 的质量滑块自由控制 JPG 压缩强度,实时显示压缩前后体积与节省率,并排预览画质差异,满意后一键导出 JPG。

This tool lets you freely control JPG compression strength via a 1-100 quality slider, shows the before/after size and savings rate in real time, previews quality side by side, and exports JPG in one click.

全部在浏览器本地完成,数据不会上传。

Everything runs locally in your browser - nothing is uploaded.

质量建议Quality suggestions

照片分享推荐 70-85,网页缩略图可用 50-70,需要保留细节时用 90 以上;质量低于 40 时画质损失明显,一般不建议。

For photo sharing use 70-85; web thumbnails can go 50-70; keep 90+ when details matter. Below 40 the loss is usually too visible.

使用步骤How to Use

  1. 上传图片。Upload an image.
  2. 拖动质量滑块,观察体积与画质。Drag the quality slider and watch size vs quality.
  3. 满意后「导出JPG」。Click "Export JPG" when satisfied.

常见问题FAQ

Q1. 压缩后的 JPG 会变模糊吗?Q1. Does the compressed JPG get blurry?

JPG 是有损格式,质量越低压缩痕迹越明显;建议保持在 70 以上,并在预览中确认细节可接受。JPG is lossy - lower quality shows more artifacts. Keep it above 70 and verify the details in the preview.

Q2. PNG 能转成 JPG 吗?Q2. Can PNG be converted to JPG?

可以,上传 PNG / WebP 后导出为 JPG;透明区域会填充为白色。Yes - upload PNG/WebP and export as JPG; transparent areas become white.

Q3. 为什么体积反而变大了?Q3. Why did the size grow?

当原图已是高压缩或小尺寸时,高质量重编码可能更大;把质量调低或换用原始文件即可。If the source is already highly compressed or tiny, re-encoding at high quality can grow it - lower the quality or use the original.