OptiDrop

Scan & Clean Signatures Online — White Background, Under 20KB

Turn messy phone-taken signature photos into clean black-and-white images with a pure white background. Output is under 20KB by default — ready for UPSC, SSC, IBPS, SBI, railways, and all government portals. Everything runs in your browser; your files never leave your device.

Drop Signature Photo Here or Tap to Browse

Supports JPG, PNG, WebP

No upload? Seriously. Files never leave your device.
100% Local — your file never leaves this device

Scan & Clean Signatures Online — Free, Private, No Upload

OptiDrop's Signature Scanner is a free online tool that converts messy, phone-taken signature photos into clean black-and-white images with a pure white background. Government portals, bank forms, and exam applications often reject signatures that have grey or uneven backgrounds. This tool solves that problem in one click — apply a contrast threshold, and your signature becomes crisp black ink on a clean white canvas, automatically compressed to under 20KB.

How the Signature Scanner Works

Upload a photo of your signature taken from your phone or scanner. The tool converts it to grayscale, then applies a threshold filter: every pixel brighter than the threshold becomes pure white (background), and every pixel darker becomes pure black (ink). You can adjust the threshold slider to fine-tune the result. The output is then compressed to fit within your chosen file size limit (20KB, 50KB, or 100KB) while maintaining readability. The entire process runs in your browser using the Canvas API — no files are uploaded anywhere.

Accepted by All Government Portals

The clean black-and-white signature output is accepted by UPSC, SSC, IBPS, SBI, RRB, Indian Railways, state-level recruitment boards, and other government portals that require a scanned signature upload. The file is typically under 20KB, meeting even the strictest upload limits. If your portal requires a slightly larger file, you can switch the limit to 50KB or 100KB before processing.

Frequently Asked Questions

It applies a contrast threshold to your photo. Pixels brighter than the threshold become white (background) and pixels darker become black (ink). This turns a grey, messy background into a clean white one with a crisp black signature.
The output is under 20KB by default, which meets the requirements of most government portals. You can also configure the limit to 50KB or 100KB if needed.
Yes. Use the threshold slider to fine-tune sensitivity. A lower value keeps more detail but may leave grey areas; a higher value produces a cleaner white background but may thin the signature ink.
Yes. The output is a clean black-and-white JPG under the file size limits accepted by all major government portals including UPSC, SSC, IBPS, SBI, railways, and state-level recruitment portals.