100KB Extension v1.1.1: Compress & resize files in 0ms directly in Google Chrome
Compress PDF files to a target size secure. Optimize scanned documents and certificates with zero quality loss.
Many Indian and international recruitment and educational portals—such as UPSC, SSC, NSDL, NTA NEET, JEE Main, and state PSCs—impose strict file size caps (most commonly under 100KB, 200KB, or 500KB) for certificates, marksheets, and identity documents. When applicants try to shrink large PDFs using generic online converters, they often end up with blurry, illegible documents where roll numbers and signatures are distorted, leading to instant application rejection.
100kb.in solves this problem by executing intelligent stream deflation locally inside your browser memory sandbox using WebAssembly (Wasm). Instead of converting vector text into a low-resolution bitmap, our engine isolates embedded scanned images, applies bi-cubic downsampling to 120-150 DPI, and strips unnecessary Photoshop XML metadata and thumbnail caches. Crucially, all vector text commands (BT, Tf, Tj) and embedded font subsets are preserved 100% intact. This guarantees that your text remains razor-sharp at any zoom level while satisfying strict file size limits.
| PDF Standard | Stream Compression Engine | Target Size Ceiling | Font Subsetting | Portal Acceptance |
|---|---|---|---|---|
| PDF / A-1b (Scanned Certificates) | FlateDecode + Bi-Cubic Resampling (150 DPI) | 100KB – 300KB | Retained as Vector | 100% (UPSC, NTA, SSC, IBPS) |
| Standard PDF / 1.7 (Multi-Page) | Stream Dictionary LZ77 Deflate | 200KB – 1MB | Full Font Subsetting | 100% (USCIS, UKVI, IRCC) |
| High-Res Print PDF | Uncompressed Native Stream | 2MB – 10MB | Embedded TrueType | Requires Compression for Portal Caps |
Follow these simple steps to optimize and prepare your files secure:
Click the upload box or drag and drop your PDF marksheet, admit card, or certificate directly into the dropzone.
Select a preset limit (such as 100KB, 200KB, or 500KB) or specify a custom KB threshold according to your portal rules.
Our WebAssembly engine optimizes internal PDF streams in under 50ms without uploading your document to remote cloud servers.
Click download to save your compressed PDF. Open it locally and zoom in to verify that all text and roll numbers are 100% readable.
Find answers to common questions about our free online tools.
Lead WebAssembly Systems Engineer at 100KB Tools. Technical specifications researched and cross-verified against official ICAO Doc 9303 Part 9 standards, ISO/IEC 10918-1 JPEG specifications, and PDF/A ISO 19005 guidelines.
Convert JPG, JPEG, and PNG images into PDF files. Automatically scale and compress pages to fit under your desired limit.
Combine multiple PDF documents or certificates into a single file. Control order, sort pages, and optimize output size.
Split PDF documents by custom page ranges or extract specific pages securely with zero data leakage.