JPG 转 PNG 在线转换器

只需 3 步，轻松将您的 JPG 文件转换为 PNG 格式。

PNG⌄

Your file will be uploaded to DigitalOfficePro storage. By using this service, you agree to the DigitalOfficePro Terms of Use.

⚙ 可选设置

Resize

Color Filter

DPI

dpi

Crop (px)

FAQ

常见问题

关于 JPG 转换为 PNG。

这个 JPG 转 PNG 转换器免费吗？

是的，我们的转换器 100% 免费。无需注册，无隐藏费用。

将 JPG 转换为 PNG 需要多长时间？

通过我们强大的云服务器，转换通常只需几秒钟。

我的 JPG 文件安全吗？

是的。您的文件在转换后立即被删除。

最大文件大小是多少？

您可以免费转换最大 400MB 的文件。

我需要安装软件吗？

无需安装。我们的转换器完全在您的网络浏览器中运行。

将 JPG 转换为 PNG

当您需要无损质量或透明背景时，JPG转PNG是必不可少的。JPG的有损压缩非常适合照片，但会在锐利边缘周围产生伪影——标志、文字和图标看起来模糊。PNG完整保留每个像素并支持完整的Alpha透明度，是网页图形、UI素材和印刷艺术品的行业标准。

为什么将 JPG 转换为 PNG？

🖼️

透明背景

PNG支持完整的Alpha透明度。从JPG转换后可以干净地去除背景。

✍️

文字和标志

PNG中的文字和纯色形状边缘保持清晰无伪影，不像JPG中的模糊光晕。

🔄

非破坏性编辑

PNG重新保存时不会降低质量。可以反复编辑和导出而不会出现质量退化。

🌐

网页UI素材

图标、按钮和界面元素以PNG格式在任何高DPI显示器上看起来像素完美。

JPG

文件扩展名.jpg
描述JPEG (Joint Photographic Experts Group) is the most widely used lossy image compression format, ideal for photographs and complex images with many colors. JPEG achieves small file sizes by discarding some image data, making it perfect for web use and sharing.
相关程序Adobe Photoshop, GIMP, Windows Photo Viewer, Preview (Mac)
开发者Joint Photographic Experts Group
MIME 类型image/jpeg

PNG

文件扩展名.png
描述PNG (Portable Network Graphics) is a lossless raster image format that supports transparency. Ideal for graphics, logos, icons, and images that require a transparent background.
相关程序Adobe Photoshop, GIMP, Microsoft Paint, Preview (Mac)
开发者PNG Development Group
MIME 类型image/png

如何将 JPG 转换为 PNG？

只需 3 步，轻松将您的 JPG 文件转换为 PNG 格式。

Step 01

上传您的 JPG 文件

点击「选择文件」或将您的 JPG 图片拖放上传。

Step 02

选择 PNG 作为输出格式

从下拉菜单中选择「PNG」作为所需输出格式。

Step 03

转换文件

点击「立即转换」开始将 JPG 文件转换为 PNG。

Step 04

下载 PNG 文件

转换完成后，下载您已转换的 PNG 文件。

💡

Tip: JPG转PNG不会恢复原始JPG压缩中丢失的质量。PNG保留JPG现有的质量——不会进一步损失。

免费 JPG 转换工具

JPG vs PNG：完整格式指南

功能

JPG

PNG

压缩

JPGLossy

PNGLossless

透明度

JPGNot supported — transparent areas always render as solid white or the specified matte color

PNGFull 8-bit alpha channel — each pixel can be any opacity level from fully transparent (0) to fully opaque (255)

动画

JPGNot supported

PNGNot in standard PNG; APNG (Animated PNG) is a non-standard extension with limited, inconsistent support

色彩深度

JPG24-bit (8 bits per channel: RGB) — up to 16.7 million colors

PNG24-bit RGB (16.7M colors) or 32-bit RGBA (16.7M colors + full alpha); up to 48-bit for professional workflows

文件大小

JPG50 KB – 5 MB per image depending on resolution and quality setting

PNG100 KB – 10 MB — significantly larger than JPG for photographic content

浏览器支持

JPGUniversal — all browsers, all operating systems, all devices including IE6 and older smartphones

PNGUniversal — all modern browsers, operating systems, and devices including IE7+

最适合

JPGPhotos, web images

PNGGraphics, logos, UI

常见使用场景：JPG → PNG

🎨 Graphic design workflows🖥️ Web UI elements📱 App icon production🏷️ Product watermarking📸 Background removal prep🖼️ Digital illustration

⚠️Converting JPG → PNG does NOT recover quality lost to JPG compression. It creates a lossless copy of whatever quality the JPG currently has — ideal for future editing, but existing compression artifacts cannot be reversed.

JPG

关于 {from} 格式 JPG

Standardized in 1992 by the Joint Photographic Experts Group, JPEG became the internet's dominant image format through the 1990s. Its DCT compression made digital photography practical for early web and digital cameras, enabling photo-sharing at a time when dial-up connections made large files impractical. Today it remains the default format for cameras, smartphones, and photo-sharing platforms worldwide.

优点

+Smallest file sizes for photographs (10:1 to 20:1 compression ratio)

+Universal compatibility across every device, software, and platform

+Embeds EXIF metadata (GPS, camera settings, date/time)

+Adjustable quality/size trade-off at save time

局限性

−Lossy — permanently discards image data with every save

−No transparency — backgrounds are always solid

−Visible block artifacts on sharp edges, text, and high-contrast areas

−Quality degrades with each re-save (generational quality loss)

使用时机

→Sharing photographs on social media, email, or blogs

→Camera images where file size matters more than pixel perfection

→Web page photos where page load speed is the priority

→Any context requiring maximum cross-device and software compatibility

提示

•Quality 85–95% delivers the optimal balance between file size and visual quality

•Never re-save a JPG after editing — use PNG or TIFF as your working master file

•Use PNG or WebP for logos, text, and graphics with sharp edges instead

•Strip EXIF metadata before web publishing to trim 5–20 KB per image

PNG

关于 {from} 格式 PNG

PNG was created in 1996 as a free, patent-unencumbered alternative to GIF after Unisys enforced its LZW compression patent. The PNG Development Group introduced full-color support, genuine alpha transparency, and superior lossless compression. It quickly became the web standard for logos, UI elements, and any image requiring a transparent background — a role it dominates to this day.

优点

+Lossless — every pixel preserved with zero compression artifacts

+Full 8-bit alpha channel for smooth, semi-transparent edges

+Ideal for text, logos, and graphics where sharpness is non-negotiable

+Unlimited re-saves without any quality degradation whatsoever

局限性

−3–5× larger than JPG for photographic content

−No native animation support in standard PNG

−Slower to load than WebP for equivalent image content

−Not practical for very high-resolution photographs at web scale

使用时机

→Logos, icons, and brand marks placed over any background color

→Screenshots where text must remain perfectly sharp

→Images edited in multiple passes (keep as the master file)

→Web UI elements, buttons, icons, and interface assets

提示

•PNG-8 (256 colors) halves the file size of PNG-24 for simple flat-color graphics

•Converting PNG to WebP typically saves ~30% file size with no visible quality change

•Alpha transparency requires PNG-24 or PNG-32 — PNG-8 only supports binary transparency

•Tools like pngquant can reduce PNG size by 50–80% with minimal quality impact

为什么选择 DigitalOfficePro？

👤

完全免费

FREE

完全免费的在线服务。无需费用，无需注册，可转换任意多个文件。

🔒

100% 安全

100%

您的文件在转换后立即从我们的服务器自动删除。

⚡

高速转换

< 3s

您的文件通过我们强大的云转换服务器进行转换。

∞

无限制

∞ files

对您可以转换的文件数量没有限制。

📤

高质量输出

HD quality

我们使用高质量的转换算法，确保转换质量。

🤝

支持 100+ 格式

200+ fmts

我们支持 200 多种文件格式。

支持的输入格式

上传以下任意格式并转换为 JPG、PNG、WEBP、BMP、GIF 或 TIFF。

标准图片

JPGPNGWEBPBMPGIFTIFFHEICPPMWBMP

设计与矢量

PSDAISVGXCFTGAPCX

RAW 相机

ARWCR2CRWDNGNEFORFPEFRAFRAWSR2MRWERFMEF3FRX3F