Compress Image to 20KB Online
Resize signatures, documents, and passport photos strictly under 20 KB for official application portals.
Strict 100% In-Browser Binary Compression
Tested on 50+ official Indian exam engines (SSC, UPSC, IBPS, NTA, Passport Seva). Zero server upload, zero data collection.
Many competitive exam portals (such as SSC, UPSC, IBPS, NTA, SBI, Railway) mandate that uploaded photos and signatures must be strictly under 20 KB in size. ResizeInKB uses intelligent browser-side optimization to compress your images precisely under 20KB while preserving clarity and facial details.
How to Compress Image to 20KB Online
- 1Upload your photo or signature by dragging & dropping or clicking 'Upload Image'.
- 2The target size is automatically pre-configured to 20 KB.
- 3Adjust crop frame or dimensions if required by your application portal.
- 4Click 'Download Compressed Image' to save your 20KB optimized photo instantly.
Target Specifications
Official Portal Upload Criteria Comparison
| Exam / Portal Name | Photo Limit | Signature Limit | Dimensions | Required Format |
|---|---|---|---|---|
| SSC (CGL/CHSL/MTS) | 20 KB - 50 KB | 10 KB - 20 KB | 3.5 x 4.5 cm | JPG / JPEG |
| UPSC Civil Services | 20 KB - 300 KB | 20 KB - 300 KB | 350x350 px min | JPG / JPEG |
| IBPS Bank Exams | 20 KB - 50 KB | 10 KB - 20 KB | 200x230 px | JPG (Black Ink) |
| NEET / JEE (NTA) | 10 KB - 200 KB | 4 KB - 30 KB | 4x6 Postcard | JPG / JPEG |
How Client-Side Image Binary Compression Works Under the Hood
When you select a target size (e.g., 20KB or 50KB), ResizeInKB executes an in-browser binary search algorithm using the HTML5 HTMLCanvasElement.toBlob() API. It dynamically adjusts JPEG quantization matrices and pixel dimensions directly inside your browser's V8 JavaScript engine memory. Because no HTTP requests send image data across the network, your processing is instant, works offline, and keeps your private photos completely secure.