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JPG to PNG Converter

Convert JPG images to lossless PNG format instantly. Preserve 100% image quality with transparency support. Free, secure, and 100% browser-based.

ここに JPG ファイルをドロップ、またはクリックして選択

JPG、JPEG ファイルに対応。最大 20 ファイル、各 20MB。

対応形式: JPG、JPEG

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可逆で保存できる

PNG にすると、今ある画質を保ったまま今後の再保存による劣化を防ぎやすくなります。

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後工程で扱いやすい

自動で背景が透明になるわけではありませんが、PNG は切り抜きやデザイン作業の中間形式として使いやすいです。

すぐに変換できる

変換はブラウザ内で完結するため、アップロード待ちがありません。

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プライバシー重視

処理はローカルで行われ、画像は外部サーバーに送信されません。

Why Convert JPG to PNG?

When you convert JPG to PNG, you move from a lossy format to a lossless one. This means your image will never degrade further, no matter how many times you edit and save it. Understanding the differences helps you decide when this conversion is worthwhile.

JPG (JPEG)

  • Lossy compression
  • No transparency support
  • Smaller file size
  • Best for photographs
  • Quality degrades on re-save

PNG

  • Lossless compression
  • Full alpha transparency
  • Larger file size
  • Best for graphics & logos
  • Quality preserved on re-save

When You Need JPG to PNG Conversion

Not every image needs to be PNG. But in these four scenarios, converting from JPG to PNG is the right call. Each use case benefits from PNG's lossless quality and transparency capabilities.

Logo & Branding

Logos need transparent backgrounds. Convert to PNG to place your logo on any background color or image without white boxes appearing around it.

Image Editing Workflows

If you plan to edit an image multiple times, work in PNG to avoid compounding JPG compression artifacts with each save cycle.

Web Graphics & Screenshots

PNG excels at sharp edges, text overlays, and flat colors. Screenshots, UI mockups, diagrams, and infographics look crisper in PNG format.

Print Design

For print materials requiring maximum fidelity, PNG preserves every detail. Use PNG for source files and design assets before final output.

How to Convert JPG to PNG Online in 3 Steps

Our free JPG to PNG converter makes the process incredibly simple. Since PNG is a lossless format, there are no quality settings to worry about — every conversion produces a perfect result.

1

Upload JPG

Drag and drop your JPG or JPEG files, or click to browse.

2

Auto-Convert

Click convert. No settings needed — PNG is always lossless.

3

Download PNG

Download files individually or as a ZIP archive.

JPG vs PNG: A Technical Deep Dive

Understanding the technical differences between JPG and PNG helps you make informed decisions about when to convert. The core distinction lies in their compression algorithms: JPG uses lossy DCT (Discrete Cosine Transform) compression that permanently discards image data, while PNG uses lossless DEFLATE compression that preserves every pixel.

When a camera saves a photo as JPG, it analyzes blocks of pixels and removes subtle color variations that the human eye is unlikely to notice. This is why JPG files are much smaller. PNG, however, finds patterns in the pixel data and compresses them without removing any information — like zipping a file. The original data can be perfectly reconstructed.

FeatureJPG (JPEG)PNG
Compression TypeLossy (DCT-based)Lossless (DEFLATE)
TransparencyNot supportedFull alpha channel (32-bit)
Color Depth24-bit (16.7M colors)24-bit or 32-bit with alpha
Best Use CasePhotos, gradients, texturesGraphics, logos, screenshots, text
Typical File SizeSmaller (5-15x vs PNG)Larger but pixel-perfect
Repeated EditingQuality degrades each saveQuality always preserved
Animation SupportNot supportedAPNG (limited browser support)
Browser SupportUniversal (all browsers)Universal (all browsers)
MetadataEXIF (camera, GPS, etc.)Text chunks, ICC profiles

What Happens to File Size After Conversion?

Converting from JPG to PNG will almost always result in a larger file. This is the fundamental trade-off for lossless quality. Below is a typical comparison for the same 1920×1080 photograph:

JPG 80% quality
120 KB
JPG 100% quality
450 KB
PNG (full color)
850 KB
PNG-8 (256 colors)
180 KB

The size increase is worth it when you need lossless editing, transparency, or pixel-perfect reproduction. For web photos where loading speed is the priority, consider keeping JPG format or using our JPEG compressor instead. If you need PNG but want to reduce its size, try our PNG compressor after converting.

Tips for Getting the Best PNG Output

Use JPG to PNG conversion for graphics, logos, and screenshots — not for large photographs where file size matters.

If you need transparency later (e.g., for a logo overlay), convert to PNG now to keep your options open.

For web photos where loading speed matters more than editing flexibility, consider keeping the JPG format.

Use batch conversion to process multiple files efficiently — upload up to 20 files at once.

The original JPG quality is preserved in the PNG, but quality already lost during the initial JPG compression cannot be recovered.

After converting, you can use our PNG compressor to optimize the file size while maintaining lossless quality.

Common Questions About JPG to PNG Conversion

Does converting JPG to PNG improve image quality? No — it preserves the current quality but cannot recover data that was already discarded during JPG compression. Think of it like photocopying a photocopy: you can prevent further degradation, but you cannot restore the original. The benefit is that all future saves and edits will be lossless.

Will my PNG file be larger than the original JPG? In most cases, yes. A PNG of a typical photo will be 2-5 times larger than a JPG at 80% quality. This is the cost of lossless compression. For images with large areas of flat color (screenshots, diagrams), the difference is smaller.

Can I get a transparent background by converting JPG to PNG? No. Converting a JPG to PNG does not create transparency. The white or colored background in your JPG remains as solid pixels. To create a transparent background, you would need to use a dedicated background removal tool after conversion.

Is the conversion done on my device? Yes. TinyImagePro processes all conversions entirely in your browser using the Canvas API. Your images are never uploaded to any server, making this the most private way to convert JPG to PNG online. No account or registration is needed.

JPG から PNG への変換に関するよくある質問

はい。登録不要で、ウォーターマークもなく、利用回数制限もありません。

はい。デスクトップでは最大 20 ファイル、モバイルでは最大 10 ファイルまで同時に変換できます。

すでに失われた情報は戻りませんが、今後の再保存で追加の劣化が起きにくくなります。

PNG は可逆形式で画素情報を保持するため、一般に JPG より容量が大きくなります。

いいえ。JPG には透過情報がないため、PNG に変換しても自動で背景が透明になるわけではありません。

違いはありません。同じ形式で、拡張子の表記が異なるだけです。

いいえ。処理はすべてブラウザ内で行われます。

はい。モバイル表示に対応しており、写真ライブラリから直接選択できます。

スクリーンショット、デザイン素材、文字入り画像、今後も編集を続ける画像に向いています。

PNG から JPG への変換、JPG から PDF、画像の切り抜き、回転なども利用できます。

JPG から PNG への変換 - 無料オンラインツール | TinyImagePro