Convert JPEG to PNG Online Free
Convert JPEG to PNG for lossless editing, logo transparency extraction, and multi-generational design workflows. PNG freezes your JPEG quality in place — no further degradation on re-save. Free, private, no upload required.
The two real reasons to convert JPEG to PNG
The first reason is transparency. JPEG does not have an alpha channel — it cannot represent transparent or semi-transparent pixels. If you have a product photo on a white background and need to place it on a colored page, a banner, or a website with a non-white background, you need PNG. Designers in Figma, Sketch, and Adobe Photoshop use JPEG-to-PNG conversion as a first step before masking out backgrounds, because only PNG (or WebP) can carry the transparency that compositing requires. The second reason is multi-generational editing. Every time you save a JPEG, the lossy DCT compression runs again on already-compressed data. After three or four save cycles, an originally clean photograph develops visible 8x8-pixel block artifacts around edges and color transitions. Converting to PNG after the first save freezes those existing artifacts in place and prevents them from compounding on future saves.
What JPEG compression actually does to your pixels
JPEG compression divides an image into 8x8 pixel blocks and applies a Discrete Cosine Transform (DCT) to each block, encoding it as a sum of frequency components. High-frequency details — sharp edges, fine text, diagonal lines — require more bits to encode accurately. At lower quality settings, the encoder drops these high-frequency coefficients, which is why JPEG artifacts appear as blurry halos around text and blocky discoloration near edges. When you convert JPEG to PNG, PNG uses DEFLATE lossless compression — it stores pixel values exactly, including any DCT artifacts already present. Those artifacts are frozen but not worsened. This is why PNG is the correct format for screenshots of text, diagrams, logos, and interface mockups — any image with sharp edges where JPEG would introduce visible ringing.
PNG file size: what to expect and when it matters
PNG files are typically 3–10x larger than the equivalent JPEG depending on image content. A 500KB JPEG of a photograph might become 3–5MB as PNG because photographs have high-frequency color variation in every pixel, which PNG's compression handles less efficiently than JPEG's DCT. However, a screenshot of a user interface or a logo might only be 1.5–2x larger because large areas of solid color compress extremely well under DEFLATE. If file size is a concern and you do not need transparency, consider WebP instead — WebP lossless mode is typically 25% smaller than PNG at identical quality. PNG is the right choice when you need maximum compatibility with editing software and when transparency preservation across editing sessions is the priority.
Why Use Konverton for JPEG to PNG Conversion?
Format Conversion
Convert between JPG, PNG, WebP, HEIC, GIF, BMP, TIFF, AVIF, and ICO formats with adjustable quality settings.
Edit & Crop
Crop images with precision, resize with the dedicated resizer, and adjust brightness, contrast, color, blur, and opacity.
100% Private
All conversions happen in your browser. Your files never leave your device.
Batch Processing
Convert multiple images at once with batch processing. Apply the same settings to all files for efficient workflow.
Technical Specifications
- Lossy DCT compression (8x8 pixel blocks)
- 16M color depth (24-bit RGB)
- No alpha channel (no transparency)
- Artifacts compound on re-save
- Lossless DEFLATE compression
- Alpha channel support (transparency)
- Existing JPEG artifacts frozen, not worsened
- Native in Photoshop, GIMP, Figma, Sketch