Image Tools
JPEG Compressor
Re-encode JPEGs at the quality you actually need — typical photos shed 40–80% with no visible difference.
In short
Compress JPEG/JPG images online: re-encode at the quality you choose and see the exact savings per photo. Batch processing, fully client-side.
By NaveenKumar T · Updated
- Per-image savings shown
- 3 quality presets or a KB target
- Batch compression
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Compressing JPEG images, explained
Most JPEGs in the wild are saved at quality 92–100 — far higher than human eyes need for screen viewing — which is why re-encoding at Balanced (≈70%) routinely cuts photos by half or more with no visible change at normal sizes. The encoder is mozjpeg compiled to WebAssembly: progressive scan, optimized Huffman tables and trellis quantization, the same encoder class professional image CDNs run server-side — so even stock photos that were already optimized once typically shrink further here.
The per-card readout is the point: 4.8 MB → 1.1 MB (−77%) tells you exactly what each preset bought you. If a particular photo matters, run it at High Quality; the preset tabs re-compress the same queue so comparison is instant.
Preset arithmetic on real photographs
Content varies, but the pattern is steady. A 24-megapixel camera JPG of 8–12 MB typically lands around 3–4 MB at High Quality, 2–2.5 MB at Balanced and 1.2–1.5 MB at Max Compression. A 1600-pixel web export already saved at quality 80 tells a different story: High Quality (85) would produce a larger file, so the original is kept and the card reads 'already optimized'; Balanced trims perhaps 15–25%; Max gets 40–50% with visible softening in fine detail. Photos with large smooth areas — sky, studio backgrounds — compress far harder than foliage or fabric texture, which is why two shots from the same camera can report savings twenty points apart.
What changes besides size: the output is progressive (it sharpens in passes as it loads), chroma is subsampled 4:2:0 at every preset, and all metadata is dropped — EXIF, GPS, capture time, the embedded thumbnail and the ICC profile, with wide-gamut colors converted to sRGB during decoding. Subsampling can soften saturated red or blue text and thin colored lines, so screenshots with type belong in the PNG or WebP compressors instead. Output files are named name-compressed.jpg beside the originals. Compress once, from the best copy you have; if you need both a smaller file and smaller dimensions, resize first with the Image Resizer, since fewer pixels beats lower quality every time.
Help
Frequently asked questions
Everything you need to know about the JPEG Compressor.
01What JPEG quality does each preset use?
High Quality re-encodes at mozjpeg quality 85, Balanced at 70 and Max Compression at 50, all progressive with 4:2:0 chroma subsampling and optimised Huffman tables. Subsampling can soften saturated red or blue text, so screenshots with type belong in the PNG or WebP compressors.
02Will compressing a JPEG again and again ruin it?
Repeated re-encoding does accumulate generational loss — but ONE deliberate compression pass at a sensible quality is exactly what JPEG is designed for. Compress once from the best source you have; avoid compress-edit-compress loops (edit in PNG, export once).
03Why is a High Quality (85) re-encode so much smaller than my camera's 'fine' JPEG?
Cameras and phones save at quality 95–98 with little or no chroma subsampling and unoptimized Huffman tables — bytes spent on detail no screen shows. mozjpeg at 85 uses 4:2:0 chroma subsampling, progressive scan and optimized tables, which alone cuts 50–70% on typical photos with no visible change at normal viewing sizes. Files that were already exported at quality 80 or below will see small gains at High Quality — or none, in which case the original is kept.
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