Comparisons

PNG vs JPG: When to Use Each Format (With Examples)

February 28, 20267 min read

The Quick Answer

If you are in a hurry, here is the short version: use JPG for photographs and use PNG for graphics, screenshots, and anything that needs transparency. That single rule will steer you right about 90% of the time.

But image formats are more nuanced than a one-line summary can capture. Understanding how each format works under the hood will help you make better decisions, avoid common mistakes, and produce images that are both high quality and appropriately sized. Let's dive into the details.

How JPG Compression Works

JPG (also written as JPEG) uses lossy compression, which means it permanently discards some image data to achieve smaller file sizes. The process works as follows:

Color space conversion: The image is converted from RGB to YCbCr color space, which separates brightness from color information. Human eyes are more sensitive to brightness changes than color changes, so this separation allows the compressor to be more aggressive with color data.

Block division: The image is divided into small blocks, typically 8x8 pixels. Each block is processed independently.

DCT transformation: Each block undergoes a Discrete Cosine Transform, which converts the pixel data into frequency components. Low-frequency components represent gradual color transitions, while high-frequency components represent sharp edges and fine details.

Quantization: This is where the actual "lossy" part happens. The frequency components are divided by values from a quantization table, and the results are rounded. Higher compression (lower quality settings) uses larger quantization values, discarding more high-frequency detail. This is what creates the characteristic "JPG artifacts" you see at low quality settings.

Entropy coding: The quantized values are further compressed using lossless techniques (Huffman coding) to squeeze out the remaining redundancy.

The result is a file that can be dramatically smaller than the original pixel data while maintaining acceptable visual quality. At a quality setting of 85-90%, most people cannot distinguish a JPG from the uncompressed original in a side-by-side comparison.

The key trade-off: Every time you save a JPG, you lose a little bit of quality. If you open a JPG, edit it, and save it again as JPG, you are compressing already-compressed data, which compounds the quality loss. This is why JPG is not ideal for images that will be edited multiple times.

How PNG Compression Works

PNG uses lossless compression, which means it reduces file size without discarding any image data whatsoever. Every single pixel in a PNG file is preserved exactly as it was in the original.

PNG achieves compression through two main steps:

Filtering: Before compression, PNG applies a prediction filter to each row of pixels. Instead of storing the raw pixel values, it stores the difference between each pixel and a predicted value based on neighboring pixels. For images with smooth gradients or repeating patterns, these differences are often very small numbers (or zeros), which compress extremely well.

DEFLATE compression: The filtered data is compressed using the DEFLATE algorithm (the same algorithm used in ZIP files). DEFLATE combines LZ77 pattern matching (finding and referencing repeated byte sequences) with Huffman coding (using shorter codes for more common values).

PNG also supports an alpha channel, which stores transparency information for each pixel. This allows pixels to be fully transparent, fully opaque, or any level of semi-transparency in between. This is why PNG is the go-to format for logos, icons, and overlays that need to be placed on different colored backgrounds.

The key advantage: Because PNG is lossless, you can open, edit, and re-save a PNG file as many times as you want without any quality degradation. The file will be pixel-identical every time.

File Size Comparison: Real Numbers

The file size difference between JPG and PNG can be enormous, especially for photographs. Here are realistic numbers for common image types:

Photographs (12 megapixel camera image, 4000x3000 pixels):

Uncompressed: approximately 36 MB

PNG: approximately 15 MB

JPG at 95% quality: approximately 5 MB

JPG at 90% quality: approximately 3 MB

JPG at 80% quality: approximately 1.8 MB

Screenshot of a web page (1920x1080 pixels):

PNG: approximately 500 KB

JPG at 90% quality: approximately 300 KB (but with visible artifacts around text)

Simple graphic with flat colors and text (800x600 pixels):

PNG: approximately 25 KB

JPG at 90% quality: approximately 60 KB (larger AND lower quality)

These numbers reveal an important insight: JPG is not always smaller than PNG. For images with large areas of flat color, sharp edges, and text, PNG can actually produce smaller files than JPG while maintaining perfect quality. JPG's compression is optimized for the smooth gradients and complex color variations found in photographs, and it struggles with the sharp transitions found in graphics and text.

When to Choose JPG

JPG is the right choice in these situations:

Photographs of any kind — landscapes, portraits, food photography, travel photos, product shots, and any image captured by a camera

Images with complex color gradients — sunsets, watercolor paintings, out-of-focus backgrounds, and natural textures

Web images where file size is critical — blog post hero images, background photos, and content images where loading speed matters more than pixel-perfect quality

Sharing photos via email or messaging — JPG's universal compatibility and small file size make it ideal for sending photos to anyone

Social media uploads — most platforms re-compress uploaded images anyway, so starting with a high-quality JPG is perfectly fine

Large image galleries — when you have dozens or hundreds of images on a page, JPG's smaller file sizes mean significantly faster page loads

Recommended JPG quality settings:

95% — archival quality, nearly indistinguishable from lossless

90% — excellent quality for most purposes

85% — great balance of quality and file size (recommended default)

80% — good for web thumbnails and smaller images

Below 70% — visible artifacts become apparent, only use when file size is extremely constrained

When to Choose PNG

PNG is the right choice in these situations:

Screenshots — PNG preserves the sharp text and UI elements perfectly without introducing compression artifacts

Logos and branding graphics — crisp edges and flat colors compress efficiently with PNG and look terrible with JPG

Images that need transparency — overlays, watermarks, icons, and any graphic that needs to be placed on different backgrounds

Text-heavy images — infographics, charts, diagrams, and any image containing readable text

Graphics with flat colors — illustrations, cartoons, UI mockups, wireframes, and diagrams

Images you plan to edit repeatedly — since PNG is lossless, you can open, modify, and re-save without quality degradation

Pixel art and retro game graphics — PNG preserves every pixel exactly, which is essential for pixel-level artwork

Technical diagrams and schematics — where precision and readability of fine details matter

Common Mistakes People Make

Mistake 1: Saving photos as PNG. This is probably the most common format mistake. Saving a photograph as PNG creates an unnecessarily large file (often 5 to 10 times larger than a good JPG) with no visible quality improvement. Unless you need to edit the photo repeatedly or need transparency, JPG is always the better choice for photos.

Mistake 2: Saving screenshots as JPG. JPG compression creates visible artifacts around sharp text edges and UI elements. These artifacts make text look blurry and introduce colored halos around high-contrast edges. Screenshots should almost always be saved as PNG.

Mistake 3: Repeatedly editing and saving as JPG. Each save cycle introduces additional compression artifacts. If you need to edit an image multiple times, work with a lossless format (PNG, TIFF, or your editor's native format) and only export to JPG as the final step.

Mistake 4: Using PNG for web photos. Some developers save all website images as PNG "for quality." This bloats page sizes unnecessarily and slows down load times. Use JPG for photographic content and PNG only for graphics that genuinely benefit from it.

Mistake 5: Ignoring WebP entirely. In 2026, WebP offers the best of both worlds for web images — smaller file sizes than JPG with quality comparable to PNG. If your images are destined for the web, consider converting to WebP for optimal performance.

How to Convert Between PNG and JPG

When you need to convert between these formats, PhotoFormatLab makes it simple:

To convert PNG to JPG: Visit PhotoFormatLab's PNG to JPG converter, drag and drop your PNG files, select your desired quality level, and download the converted JPGs. This is useful when you have PNG screenshots or graphics that you want to share in a more universally compatible and smaller format.

To convert JPG to PNG: Visit PhotoFormatLab's JPG to PNG converter, drag and drop your JPG files, and download the converted PNGs. Note that converting a JPG to PNG will not improve the image quality (you cannot recover data that was already discarded by JPG compression), but it will give you a lossless file that will not degrade further if you need to edit and re-save it.

All conversions happen directly in your browser. Your files are never uploaded to any server, ensuring complete privacy.

Frequently Asked Questions

Does converting JPG to PNG improve image quality?

No. Converting from JPG to PNG does not restore any quality that was lost during JPG compression. The conversion preserves the image exactly as it is (including any existing JPG artifacts) in a lossless container. The advantage is that the PNG file will not lose any additional quality if you edit and re-save it, whereas re-saving as JPG would introduce further compression.

Which format is better for printing?

For professional printing, neither JPG nor PNG is the ideal choice — TIFF is the industry standard for print production. However, if you must choose between JPG and PNG for printing, use a high-quality JPG (95%) for photographs and PNG for graphics with text or sharp edges. The resolution and color profile matter more for print quality than the file format.

Is PNG always higher quality than JPG?

PNG is lossless, meaning it preserves every pixel perfectly. JPG is lossy, meaning some data is discarded. In that sense, PNG is "higher quality." However, at high JPG quality settings (90-95%), the difference is imperceptible to the human eye for photographs. The "quality" difference only becomes visible at lower JPG quality settings or in images with sharp edges and text.

Should I use PNG or JPG for my website?

Use JPG for photographic images (hero images, blog photos, product shots) and PNG for graphics that need transparency or contain text and sharp edges (logos, icons, diagrams). For the best web performance in 2026, consider converting both to WebP, which offers smaller file sizes than either format while supporting both lossy and lossless compression plus transparency.

Can I make a PNG file smaller without losing quality?

Yes, PNG files can be optimized without any quality loss by using more efficient compression settings. Tools that re-compress PNGs can sometimes reduce file sizes by 20-40% without changing a single pixel. However, even optimized PNGs will still be larger than equivalent JPGs for photographic content.

For professional printing workflows, see our TIFF vs JPG comparison. For social media optimization, check our image formats for social media guide.

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