Compress an image to an exact size
Name a target — 20 KB, 50 KB, 100 KB, anything — and Invo finds the highest quality that fits underneath it.
Online application forms are unforgiving about file size. Exam boards, government portals and bank KYC pages routinely demand a photo under 50 KB and a signature under 20 KB, then reject anything a single byte over.
Rather than nudging a quality slider and re-checking, set the ceiling. Invo runs a binary search across quality settings to land as close under your target as it can, and reduces resolution only if quality alone will not do it.
How to use it
- Add your photo, signature or scanned document.
- Choose a preset target or type your own in KB.
- Process. The result is guaranteed to sit under your limit.
How the exact-size fit works
File size and JPEG quality do not relate linearly, so you cannot calculate the right setting — you have to search for it. Invo encodes at a midpoint quality, checks the size, and halves the remaining range each time.
If even low quality overshoots — common when squeezing a 12 MP photo to 20 KB — resolution steps down and the search runs again. That produces a far better-looking result than crushing quality alone, which turns an image into coloured blocks.
Common form requirements
Typical limits on Indian exam and government portals:
- Photograph — 20 KB to 50 KB, JPEG, usually 3.5 × 4.5 cm
- Signature — 10 KB to 20 KB, JPEG, on white paper in black or blue ink
- Thumb impression — 20 KB to 50 KB
- Supporting documents — 100 KB to 500 KB, JPEG or PDF
- Identity scans — commonly 100 KB to 200 KB
Always confirm against the specific portal's instructions. Requirements differ, and some also enforce minimum pixel dimensions.
Order matters. If a form specifies both dimensions and a size cap, resize first, then compress. Doing it the other way round re-compresses an already-compressed image and wastes quality.
Getting a readable result at very small sizes
- Crop tight. Background pixels consume your budget.
- Resize before compressing. A 4000 px image squeezed to 20 KB looks dreadful; the same photo at 600 px looks fine.
- Scan signatures in grayscale. Colour data on black ink is pure waste — the signature cropper does this automatically.
- Avoid busy backgrounds. Plain white compresses to almost nothing.
Questions
Will the result definitely be under my target?
Yes, in essentially every case. Invo lowers quality first and reduces resolution if needed, and tells you if a target is genuinely unreachable.
Which target should I choose?
Whatever the form states. Aim slightly under, not exactly at, the limit.
Does it work for signatures?
Yes, though the dedicated signature cropper handles trimming and background cleanup as well.
Can I set a size in MB?
Enter the equivalent in KB — 1 MB is 1024 KB.
Is my document uploaded anywhere?
No. Everything is processed in your browser. For identity documents that matters.
The image looks poor at my target size.
Crop tighter and reduce the max width before compressing.