Image compressor
Drop an image, pick a quality, watch the file size fall. JPEG or WebP out, exact savings shown, and the file never leaves your browser.
What the compressor actually does
- It decodes your image and re-encodes it with the browser's own JPEG or WebP encoder at the quality you set. No AI upscaling, no server round trip, no metadata kept: EXIF data (including location) is stripped as a side effect of re-encoding.
- The quality slider is honest: 80% is the sweet spot for photos, 60% shows artifacts in gradients, above 90% the file grows fast for invisible gains.
- The dimension cap does most of the work on phone photos: halving the pixel width cuts the file roughly by four before quality even enters it.
- Transparent PNGs flatten to white in JPEG mode; pick WebP to keep transparency at a small size.
Frequently asked questions
How do I reduce an image's file size without losing quality?
Two levers: re-encode at a lower quality setting (80% JPEG is visually identical to 100% for photos at a fraction of the size) and cap the pixel dimensions (a 6000px phone photo displayed at 1080px carries 30x the data anyone sees). This tool applies both and shows the exact savings before you download.
JPEG or WebP, which should I pick?
WebP compresses 25 to 35% smaller than JPEG at the same visual quality and every modern browser and network accepts it. JPEG remains the safe answer for maximum compatibility with older software. For social uploads, either works; the networks re-encode anyway.
Is the image uploaded to a server?
No. Compression runs in your browser using the canvas API. The file never leaves your machine, which also means there is no size limit beyond what your device handles.
Why compress images before posting to social media?
Networks accept big files but their compressors punish them: a 12MB upload gets squeezed through aggressive re-encoding tuned for speed, not quality. Uploading a clean, reasonably-sized file (under about 1MB for a post image) consistently survives the platform's pipeline better.
What does the longest-side cap do?
It scales the image down so its longer edge fits the cap, keeping the aspect ratio. Since Instagram renders at 1080 wide and X at 1600, pixels beyond roughly 2048 are wasted bytes for social posts.
Compressed in a second. Posted on schedule.
posthell takes the post from here: attach the image once, tailor the text per network, and it publishes to 15 networks at the times you pick.