Universal image reducer
Image Size Reducer in KB
Reduce any photo to your exact KB target — from 20 KB signatures to 500 KB high-quality portraits. Browser-only. No upload, no signup, no watermark.
Ready to reduce your image?
Open the tool → pick photo and your KB target
Pick your KB target
Common KB targets for upload portals:
How browser-based KB reduction works
UploadReady uses the HTML5 Canvas API to re-encode your image at progressively lower JPG or WebP quality settings. It runs a binary search: starting at quality 95, the tool checks the resulting file size, halves the quality range, and re-encodes — typically reaching your KB target within 4-7 iterations. For PNG (lossless format), it reduces dimensions instead. All this happens in your browser's JavaScript engine — no network calls, no server, no waiting for upload.
Perfect for...
- Any form portal with a specific KB upload ceiling
- Mobile data savers — reduce before sending via WhatsApp/email
- Privacy-conscious users — file never leaves your device
- Offline use — works without internet once the page is loaded
Tips for choosing the right KB target
- Read the portal's spec first. Most upload forms display "max 100 KB" or similar — match exactly, not below.
- For face photos under 50 KB → use JPG output, expect noticeable quality drop. Don't pick lower than required.
- For signatures under 20 KB → PNG works because signatures are high-contrast and dimension-reducible.
- Keep margin. If portal says "max 100 KB", target 90 KB to avoid edge-case rejection.
FAQ
What KB sizes can I reduce to?
20 KB to 500 KB via presets, up to 2 MB manual. Most common: 20 KB (signature), 100-200 KB (ID), 500 KB (high-quality).
How does the reducer pick quality?
Binary search on JPG/WebP quality 95 down to 20, encoding test rounds until ±5% of target. PNG reduces dimensions instead.
Why browser-based over desktop?
Privacy (no upload), speed (no install), convenience (any device). Desktop tools overkill for one-off KB targeting.
Reduce size without changing dimensions?
Yes — use Compress mode. Keeps dimensions, only file size drops via quality tuning.
Smallest usable KB target?
20 KB for face photos. 5-10 KB OK for signatures (line art). Below 10 KB face photos become unusable.
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