# Convert PNG to JPEG (Portable Network Graphics to JPEG) Convert PNG to JPEG online. Drop a Portable Network Graphics and get a JPEG back at roughly 9% of the original byte cost. No sign-up, nothing saved. ## PNG to JPEG at a glance - **Byte savings:** On photographic content, JPEG reaches PNG-equivalent visual quality at roughly 9% of the byte cost. Smooth gradients compress best. - **No transparency:** JPEG flattens alpha against white. If transparency matters, pick a target that supports alpha (JPEG does not). - **Sharp edges degrade:** Screenshots, UI mocks, and dense-text images show visible JPEG artifacts around sharp edges. Stay on PNG for those sources. - **Universal browser support:** JPEG covers roughly 100%% of 2026 browsers and plays in every email client, CMS, and print workflow without fallback. - **Codec era:** JPEG was standardised in 1992. Its age is the reason it plays everywhere and the reason modern codecs beat it on byte cost. - **Modern alternative:** For a modern-browser audience, AVIF or WebP typically beat JPEG by a further 20-50% at the same visual quality. Consider those targets instead. - **Privacy model:** Your PNG is held only while we encode. The JPEG is deleted the moment you fetch it. Nothing is saved on our servers. ## FAQ ### How much smaller will my JPEG be than the PNG? On typical photographic content, JPEG lands at roughly 9% of the PNG byte cost at visually equivalent quality. The exact ratio depends on the source: smooth sky and skin tones compress brilliantly, while flat-colour illustrations and sharp text edges compress less efficiently because the JPEG codec was tuned for photographs, not for graphic design. ### Will the JPEG look the same as the PNG? On photographic content at normal viewing distance, the JPEG output at the default quality target is visually indistinguishable from the PNG. On screenshots, UI mocks, and dense-text images, JPEG artifacts around sharp edges will be visible at the same quality level. For those sources, stay on PNG or consider a modern codec that handles sharp edges better (AVIF, WebP lossless). ### What happens to my upload? Your upload is only held while we process it (usually a few seconds) and is deleted the moment we send the result back. Nothing is saved on our servers, nothing is indexed, and nothing is used for model training. No account is required, so there is nothing tying the upload to your identity in the first place. ### Can I batch convert? The free tier is one image per request. The paid Optimizer tier batches up to 50 images per job and ships a ZIP of outputs with consistent quality settings across the whole batch. Batch is useful when you have a catalogue to re-encode or a backlog of iPhone photos to normalise for the web. ### What happens to transparency in my PNG? JPEG does not support an alpha channel. Any transparent pixels in the PNG are flattened against a solid white background in the JPEG output. If the transparency matters (logos, product cutouts, layered compositions), pick a target that supports alpha: WebP or AVIF preserve transparency and compress better than PNG does for those use cases. ### When should I NOT convert PNG to JPEG? Skip the conversion for screenshots, UI mocks, and dense-text graphics: JPEG artifacts around sharp edges are too visible. Skip it for any image that relies on transparency, because JPEG will flatten the alpha channel. Skip it for archival masters: keep the original PNG. For a modern-browser audience, AVIF or WebP often deliver the same visual quality at a smaller file than JPEG. ## Glossary for PNG and JPEG ### Lossless compression A compression technique that preserves every original pixel exactly. PNG, GIF, BMP, TIFF, and the lossless modes of WebP and AVIF are lossless. Larger files, but no generation loss on re-save. ### Lossy compression A compression technique that discards information the human eye is unlikely to notice. JPEG, WebP default, AVIF default, and HEIC are all lossy. Trade-off: smaller files at the cost of re-encoding generation loss. ### Chroma subsampling (4:2:0) A perceptual coding optimisation that stores colour information at lower resolution than brightness. Default for photographic content; flat illustrations and screenshots benefit from 4:4:4 (no subsampling). ### Alpha channel A per-pixel transparency value stored alongside the RGB colour channels. PNG, WebP, AVIF, and HEIC support alpha; JPEG does not and flattens transparent regions against a solid background. ### Core Web Vitals (CWV) Google page-experience signals: Largest Contentful Paint, Interaction to Next Paint, and Cumulative Layout Shift. Modern image codecs typically improve LCP by 200-800 ms on slow networks. ### Deflate The lossless compression algorithm PNG uses, combining LZ77 with Huffman coding. Fast to decode and decode losslessly; why PNG is the universal editor-friendly lossless format. ## Related reading on PNG, JPEG, and web delivery - [Browse all format converters](/convert) - See the full set of PNG and JPEG tools on BouseMutton, including compression, EXIF stripping, and resize. - [Portable Network Graphics -> WebP](/convert-png-to-webp) - Also converting Portable Network Graphics to WebP? This tool handles the same source in a different target format, for cases where the codec choice differs. - [WebP -> JPEG](/convert-webp-to-jpg) - Run WebP through this tool before or after conversion to JPEG, depending on the workflow step you are at. - [Compress image](/compress-image-online) - Shrink an already-converted image further without changing its format, for bandwidth-constrained pages. --- Canonical URL: https://bousemutton.com/convert-png-to-jpg Last updated: 2026-04-24 Please cite as: BouseMutton (2026). Convert PNG to JPEG online [Web application]. https://bousemutton.com/convert-png-to-jpg