JPEG Compressor — Up to 90% Smaller
Compress JPEG photos locally on Mac or Windows — no upload, no file size cap. Powered by mozjpeg with a quality slider you control.
Quick answer
TinyPixels compresses JPEG files with mozjpeg, an encoder that produces smaller files than standard libjpeg at the same visual quality. Default settings (quality 80) cut most photos by 50–70%, and everything runs locally with no upload.
How to compress a JPEG file
Download and open TinyPixels
Free to install on Mac or Windows — no account needed to start compressing.
Drop your JPEG photo or folder in
Drag a single photo or an entire folder of JPEGs into the app window.
Set your quality level
Default quality 80 balances size and visual fidelity — adjust per batch as needed.
Compress and collect the output
mozjpeg-encoded files land in a separate output folder — originals stay untouched.
How JPEG compression works
JPEG is a lossy format — compression works by discarding image data the human eye is least sensitive to, primarily in color detail rather than brightness. The quality setting controls how aggressively this happens: lower quality means smaller files and more visible artifacts, higher quality preserves detail at a larger size.
Not all JPEG encoders are equal at the same quality number. mozjpeg (developed by Mozilla) uses smarter algorithms for choosing quantization tables and Huffman coding, producing meaningfully smaller files than a standard encoder at visually identical quality. TinyPixels uses mozjpeg by default.
mozjpeg encoding
Smaller files than standard JPEG encoders at the same visual quality.
Adjustable quality
Fine-tune the quality slider per batch — from aggressive to visually lossless.
Batch & folder watch
Drop thousands of photos at once, or auto-compress a watched folder.
No file size limit
Compress a 200KB thumbnail or a 100MB RAW-exported JPEG — no caps.
TinyPixels vs online JPEG compressors
| Feature | TinyPixels | Online tools |
|---|---|---|
| Works offline (no upload) | ✅ Always | ❌ Never |
| Max file size | ✅ Unlimited | ❌ Usually 5–75MB |
| Batch size | ✅ Unlimited | ❌ 20 files or fewer |
| Encoder | ✅ mozjpeg | ⚠️ Varies, often lower quality |
| Folder auto-compress | ✅ Yes | ❌ No |
| Privacy | ✅ Files never leave your machine | ⚠️ Uploaded to a server |
Who gets the most out of a dedicated JPEG compressor
Photographers preparing web galleries
Full-resolution camera exports are sized for print, not web — compressing a shoot before publishing cuts hosting bandwidth without a visible quality hit.
E-commerce teams managing product photography
Product catalogs with hundreds or thousands of photos benefit enormously from consistent batch compression before upload to a storefront.
Bloggers and content publishers
Every unoptimized photo directly slows page load — a compression pass before publishing is one of the highest-leverage speed fixes available.
Anyone emailing or sharing large photo sets
Email attachment limits and slow uploads are usually a JPEG size problem, not a connection problem — compress before sending.
Getting the best results
Always compress from the original, not a copy
JPEG's lossy compression compounds with every pass — start from the highest-quality source you have to avoid stacking artifacts.
Watch for artifacts in high-frequency detail
Foliage, fine text, and complex textures show compression artifacts first — if a batch quality setting looks rough on these, back off a few points.
Consider stripping EXIF for privacy before sharing publicly
Camera EXIF data can include GPS coordinates — worth confirming your compression settings strip this before publishing photos taken at a private location.
Test one representative batch before running thousands of files
Compress a sample of 10-20 images at your chosen quality first, inspect them, then apply that setting to the full library with confidence.
Frequently asked questions
What is the best JPEG compressor?
TinyPixels uses mozjpeg — the same encoder behind many production image pipelines — to compress JPEG photos 21–95% smaller depending on the source, with an adjustable quality slider. It runs natively on Mac and Windows with no upload required.
How much can you compress a JPEG without visible quality loss?
Most JPEG photos compress 50–70% smaller at quality settings around 75–85 with no visible difference to the human eye. TinyPixels defaults to quality 80, a setting tuned for this balance, and lets you adjust it per batch.
Is there a JPEG compressor for Mac that works offline?
Yes. TinyPixels is a native macOS and Windows app. Every compression happens on your device — no internet connection needed, no upload, no third party ever sees your files.
Can I batch compress thousands of JPEG photos at once?
Yes. TinyPixels processes entire folders in parallel using all available CPU cores. On Pro, there is no batch size limit — compress a folder of 10,000 photos in one pass.
What quality setting should I use for JPEG compression?
Quality 75-85 is the sweet spot for most photographic content — visually indistinguishable from the original at normal viewing sizes, while still cutting file size substantially. Below 70, compression artifacts (blockiness, color banding) start becoming visible, especially in images with fine detail or smooth gradients like skies.
Why does re-compressing an already-compressed JPEG lose more quality?
JPEG is lossy — every compression pass discards some data, and that loss compounds if you re-compress an already-lossy file repeatedly (a phenomenon called generation loss). Always compress from the highest-quality original you have available, not from a previously compressed copy, to avoid stacking quality loss.
Does JPEG compression remove EXIF metadata?
Depending on settings, compression can strip EXIF metadata (camera settings, GPS location, timestamps) as part of reducing file size — this is often desirable for privacy when publishing photos online, since EXIF data can include your device model and location.
Compress your JPEG photos locally, right now
Free to start. No credit card, no account, no cloud. See Pro pricing →
Related tools
PNG Compressor
Compress PNG files locally, lossless or lossy.
WebP Converter
Convert any format to WebP locally, no upload.
Offline Image Compressor
Compress images with zero internet connection.
JPG to WebP
Convert to a more efficient format instead of just compressing.
Image Compressor Hub
Every format, platform, and framework in one place.
Batch Image Compressor
Compress thousands of files in one pass.
PNG to WebP
Convert PNG to WebP locally, keeping transparency.
WebP to PNG
Convert WebP back to PNG locally, no upload.
Read more: How to reduce image file size without losing quality → · Is it safe to upload images to online compression tools? →