PNG vs JPG: When to Use Each Format (With Examples)
The Core Difference: How Each Format Handles Compression
PNG and JPG are not interchangeable tools — they solve different problems. JPG (also written JPEG) uses lossy compression, meaning it permanently discards pixel data to shrink file size. Every time you save a JPG, an algorithm groups similar-colored pixels together and averages them out. The result is smaller files, but with visible artifacts if you push compression too hard. A quality setting of 80 in Photoshop (File > Export > Export As > Quality slider) gives you roughly 60–70% size reduction with minimal visible loss on photographs. Drop to quality 40 and you'll start seeing blocky squares — called macroblocking — especially around high-contrast edges like text on a colored background. PNG uses lossless compression. Every single pixel is preserved exactly as it was recorded. The compression algorithm (DEFLATE) finds repeating patterns in the data and stores them efficiently, but it never throws anything away. Open a PNG, save it again, open it again — the pixel values are identical every time. This makes PNG the correct choice when fidelity is non-negotiable. The practical consequence: a 4000×3000 photograph of a mountain landscape saved as a high-quality JPG might be 3–5 MB. The same image saved as PNG might be 25–40 MB. For that photograph, the extra size buys you almost nothing visible. But a 1200×800 screenshot of a spreadsheet saved as JPG at quality 75 will show smeared text and color fringing around cell borders. Saved as PNG, it stays razor-sharp at maybe 300–500 KB. The format choice should always follow the content type, not habit.
When JPG Is the Right Call
JPG was designed for photographs, and that is still where it excels. The format's lossy compression exploits a quirk of human vision: we're less sensitive to subtle color variations than to sharp edges. Photographs are full of gradual tonal transitions — the sky fading from deep blue to pale at the horizon, skin tones shifting across a face in soft light — and JPG compresses those transitions aggressively without most viewers noticing. Use JPG for: **Camera photos destined for the web.** A product photo for an e-commerce site, a hero image for a blog post, a travel photo for Instagram. At quality 75–85, a typical DSLR image compresses to under 500 KB while looking indistinguishable from the original at normal viewing sizes. **Any image where file size matters more than pixel-perfect accuracy.** Email attachments, images embedded in PDF documents for distribution, thumbnails. Google's own PageSpeed guidelines recommend serving images under 200 KB where possible; JPG almost always gets you there faster than PNG for photographic content. **Images that won't be re-edited.** Because JPG is lossy, every save cycle degrades the file slightly. If you're exporting a final version of a photo that you'll never open and re-save in a lossy format again, JPG is fine. If you're working on an image iteratively, keep your master in a lossless format (PNG, TIFF, or a raw format) and export to JPG only at the final step. One honest caveat: JPG does not support transparency. If your photograph needs a transparent background — say, a product shot you want to composite onto different backgrounds — JPG cannot do that job. You'll need PNG or WebP.
When PNG Is the Right Call
PNG's lossless nature and transparency support make it the correct format for a specific set of use cases that JPG handles badly. **Screenshots and screen recordings exported as stills.** Text rendered on a monitor is high-contrast and hard-edged. JPG compression introduces color fringing around letterforms that makes text look blurry even at high quality settings. A screenshot of a code editor, a UI mockup, or a financial dashboard belongs in PNG. **Logos, icons, and illustrations with flat or limited color areas.** A company logo with a white background that needs to be placed on various colored surfaces needs a transparent PNG. A vector illustration exported from Illustrator (File > Export > Export As > PNG, check Use Artboards) preserves every sharp edge. The same export as JPG would add a white background and blur the edges slightly. **Images used in further editing workflows.** If a designer is going to receive your file and composite it, mask it, or adjust it, give them PNG. The lossless format means no generation loss accumulates as the file passes through multiple applications. **Images with large areas of solid color.** Infographics, charts, diagrams, and flat-design illustrations often have large blocks of a single color. PNG's DEFLATE compression handles these extremely efficiently — sometimes producing smaller files than JPG would at equivalent quality — because repeating identical pixels compress down to almost nothing. PNG's main limitation is file size for photographic content. A 24-bit PNG of a complex photograph will almost always be larger than a well-compressed JPG of the same image with no perceptible quality difference. For photographs, that size premium is rarely justified.
Side-by-Side Examples With Real Numbers
Abstract comparisons only go so far. Here are three concrete examples with actual file sizes to make the tradeoffs tangible. **Example 1: Product photograph (2400×1600 px, camera photo of running shoes)** - JPG at quality 85: 487 KB — clean, no visible artifacts - JPG at quality 60: 198 KB — slight softness in texture details, acceptable for thumbnails - PNG (24-bit): 6.2 MB — identical quality to the original, but 12× larger than the quality-85 JPG Verdict: JPG wins decisively. The PNG offers no visible benefit and would significantly slow page load. **Example 2: UI screenshot (1440×900 px, web browser with text-heavy page)** - JPG at quality 85: 312 KB — noticeable color fringing around black text, especially at small font sizes - JPG at quality 95: 890 KB — fringing reduced but still present on 12px body text - PNG (24-bit): 418 KB — perfectly sharp text, no artifacts Verdict: PNG wins. It's actually smaller than the high-quality JPG and looks better. **Example 3: Company logo (800×400 px, flat design with transparent background)** - JPG at quality 90: 45 KB — transparency impossible; white background forced in; soft edges - PNG (24-bit with alpha): 38 KB — full transparency, crisp edges Verdict: PNG is both smaller and technically capable of what the job requires. JPG can't even attempt transparency. These numbers will vary depending on image content, but the patterns they illustrate are consistent across thousands of real-world files.
Converting Between PNG and JPG: What to Expect
Converting a JPG to PNG does not recover lost data. If a photo was saved as JPG at quality 70 and then converted to PNG, the PNG will be a lossless copy of an already-compressed image — you've preserved the artifacts, not removed them. The file will be larger but not better. This is a common misconception worth addressing plainly. Converting PNG to JPG is straightforward and usually sensible when you're moving a photograph from an editing workflow to web delivery. The conversion applies JPG compression for the first time, so you choose the quality level at that point. CocoConvert's PNG-to-JPG converter lets you set the quality level from 1 to 100 before converting; quality 82 is a reasonable default for most web-use photographs. Converting JPG to PNG makes practical sense in a few scenarios: you need to add transparency to an existing photo (though you'll need to do the masking work elsewhere — CocoConvert's converter handles the format change, not background removal), or you're archiving files and want a lossless container going forward. Just know the original compression damage from the JPG stage is already baked in. Batch conversion is where a tool like CocoConvert saves meaningful time. If you have 200 product photos in PNG format left over from a design workflow and need to publish them to a website, converting them all to JPG at quality 80 in one operation is faster than opening each one in Photoshop. CocoConvert's batch upload accepts up to 50 files at once on the free plan and 500 on the Pro plan. It does not currently support folder watching or automated API-triggered conversion — if you need that, you're looking at tools like Cloudinary or ImageMagick scripts.
What About WebP, AVIF, and Other Modern Formats?
PNG and JPG have been the dominant web image formats for over two decades, but they're not the only options anymore. WebP, developed by Google and now supported by all major browsers (Chrome, Firefox, Safari 14+, Edge), offers both lossy and lossless modes. A WebP image in lossy mode is typically 25–35% smaller than a comparable JPG at equivalent visual quality. WebP in lossless mode is typically 20–30% smaller than PNG for the same image. AVIF is newer still, based on the AV1 video codec. It achieves even better compression than WebP — often 40–50% smaller than JPG — and handles HDR content well. Browser support is now solid (Chrome 85+, Firefox 93+, Safari 16+), but encoding is slower and tooling is less mature. So why are we still talking about PNG and JPG? Several reasons. First, compatibility: JPG and PNG work everywhere, including older software, email clients, and systems that don't touch the web. Second, familiarity: most clients, contractors, and print vendors expect JPG or PNG and may not accept WebP. Third, many workflows still require them — stock photo platforms, print-on-demand services, and CMS platforms often mandate JPG or PNG uploads. CocoConvert supports conversion to and from WebP, so if your target environment supports it, converting your JPGs and PNGs to WebP before upload is worth doing. AVIF conversion is on the roadmap but not yet available. For now, if you're building a modern web project and control the full stack, consider WebP as your delivery format while keeping PNG or high-quality JPG as your source files.
A Practical Decision Framework
After working through all the technical details, a simple decision process covers the majority of real-world situations. **Start with the content type:** - Photograph or photorealistic rendering → JPG, unless you need transparency - Screenshot, UI element, diagram, illustration, or logo → PNG - Transparent background required → PNG (or WebP if browser-only delivery) **Then consider the destination:** - Web delivery where page speed matters → JPG at quality 75–85 for photos; PNG for graphics; WebP if supported - Print or archival storage → PNG or TIFF; avoid JPG for anything you'll re-edit - Email attachment → JPG for photos (keep under 1 MB); PNG for screenshots - Social media → JPG for photos (platforms recompress anyway); PNG for graphics with text **Watch out for these common mistakes:** - Saving a logo or diagram as JPG and wondering why it looks blurry - Keeping large PNG photographs on a website and wondering why it loads slowly - Converting JPG to PNG expecting quality improvement - Using quality settings below 70 for JPG and expecting clean results on text or high-contrast edges If you're ever unsure, open both exports at 100% zoom and look at the sharpest edges in the image — usually text, line art, or hard geometric shapes. If the JPG looks clean there, it'll look clean everywhere. If you see color fringing or blockiness, switch to PNG. CocoConvert's converter handles the mechanical part of format switching reliably and quickly. What it can't do is make the creative judgment call for you — that requires understanding what the image contains and where it's going. The framework above should make that judgment straightforward for most files you encounter.