Byteshrink — Compress PDFs & Images Entirely in Your Browser
A privacy-first web app that compresses PDFs and images right in your browser — no uploads, no servers, no data leaving your device.
- The question
- The tool needed to compress PDFs and images without server uploads, giving users control over quality, format, and resizing while keeping files private, plus a cropping tool with export formats.
- Stack & tools
- Next.js, TypeScript, React, Tailwind CSS, Canvas API, OffscreenCanvas, Web Workers, pdf-lib, pdf.js, pica, react-easy-crop, JSZip, Zustand
- What I found
- The finished tool compresses files instantly right in the browser, often shrinking sizes by 60-80% with barely noticeable quality loss, while giving users precise, adjustable controls and complete file privacy.
I built Byteshrink because I kept running into the same annoying problem over and over: I needed to shrink a PDF or an image quickly, and every "free" tool online wanted me to upload my file to some random server first. Half the time I had no idea where that file actually went, who could see it, or how long it stuck around. For anything even slightly sensitive — a contract, a scanned ID, a client document — that always made me uneasy. I figured there had to be a better way, and honestly, there was: the browser itself is powerful enough to handle real compression work without ever touching a server.
I started with pen and paper, sketching out what the flow should feel like. My first instinct was to cram everything onto one screen — upload, settings, crop, download — but that felt cluttered the moment I drew it out. Breaking it into a step-by-step wizard made everything click. Each screen could focus on exactly one decision: pick your file, choose your settings, crop if you need to, then download. Simple, and easy to follow even for someone who's never used a tool like this.
The technical side took the most trial and error. Getting image compression to run entirely client-side using the Canvas API was straightforward enough, but PDFs were a different story — I spent a good stretch just understanding how PDF streams and embedded images actually work under the hood so I could shrink them without visibly degrading the document. Getting the crop tool to feel smooth on both a mouse and a touchscreen took several rebuilds before it finally felt natural instead of fiddly.
Design-wise, I didn't want this to look like every other generic file-conversion site out there — the kind with a stock hero image and a wall of ads. I picked a blue-and-amber color pair that felt fresh without being trendy for trendiness's sake, built a small monogram icon, and kept the layout deliberately spacious. A tool built around speed shouldn't feel cluttered or busy.
By the time I had a working version, the payoff was obvious: drop in a file, watch it shrink by 70-80% in seconds, right there in the browser tab, with nothing ever leaving my machine. That first successful compression — watching a 5MB PDF turn into 900KB with barely any visible quality difference — is still the moment I'm proudest of in this whole project.
Gallery
Platforms I've helped build for
Kind words
Don't just take my word for it
Notes from teammates and client stakeholders I've worked alongside.
Had the pleasure of working closely with Sanjiv, and he is an exceptional leader who seamlessly bridges high-level strategy with deep technical execution.
Sanjiv excels in technical problem-solving—when complex, high-stakes engineering or architectural challenges arise, he is the person you want in the room. He approaches problems analytically, quickly getting to the root cause and devising elegant, scalable solutions.
Beyond his technical acumen, Sanjiv is a standout leader in solution delivery and team management. He has a proven ability to align cross-functional teams, streamline processes, and keep project milestones on track without sacrificing quality. His clear communication, structured approach, and genuine investment in supporting team members make him a trusted partner and a pillar on any team.
I highly recommend Sanjiv to any organization looking for a strong technical strategist and reliable leader who consistently delivers results.
Aman Kumar Sinha(LinkedIn profile, opens in a new tab)
Senior Product Manager at Merkle Sokrati · Oct 2026
