Free Online Tools

About Our Tools

ZeroDataUpload started with a simple idea: everyday tasks like compressing files, generating passwords, and converting images shouldn't require you to hand your data over to a stranger's server. We've all been there — you need to remove a few pages from a PDF, so you search for an online tool, upload the document, wait for it to process on some remote machine, and hope that your file gets deleted afterward. Most of the time, you have no idea what happens to that file once it leaves your computer. It could be cached, logged, analyzed, or stored indefinitely.

We decided to build things differently. Every tool on ZeroDataUpload runs entirely inside your web browser. When you compress a ZIP file, add a watermark to a photo, or generate a secure password, the work happens right on your own device. Your files never travel across the internet to reach a processing server. There is no upload step, no waiting in a queue, and no cloud storage involved. You open the tool, use it, and close the tab. Your data stays with you the entire time.

The collection currently includes 31 tools and converters organized across categories like productivity, developer utilities, media editing, text processing, security, design, and more. On the productivity side, you'll find tools for working with PDF documents — merging, splitting, compressing, adding watermarks, redacting sensitive information, and even extracting text from scanned pages. For developers, there's an epoch timestamp converter that handles 418 timezones, a UUID generator supporting multiple versions with bulk generation, a favicon creator that outputs every format you need for web and mobile, and encoding tools for Base64, hexadecimal, binary, and more.

If you work with media, you can add watermarks to batches of photos, convert images between formats like HEIC, WebP, AVIF, PNG, and JPG, or convert audio and video files between dozens of formats. There's a passport photo maker that covers specifications for over 70 countries, an OCR tool that extracts text from images in 18 languages, and a system information tool that reads your device's hardware details directly in the browser.

On the lighter side, we've also built a coin flipper with cryptographically fair randomness, a multi-dice roller with 3D physics, and a picture puzzle game you can play with your own photos. These might seem out of place alongside serious utilities, but they use the same privacy-first approach — no tracking, no accounts, no data collection.

The converter collection is just as deep. You can convert spreadsheets between Excel, CSV, JSON, and XML formats. Transform documents between Word, PDF, plain text, HTML, and Markdown. Convert ebooks between EPUB, PDF, and other formats. Shift email archives between EML, MBOX, and MSG. Convert fonts between different web and desktop formats. Translate between color spaces, currency values with live exchange rates, measurement units across 17 categories, number bases, timezones with daylight saving awareness, and various text encodings including Morse code, Braille, and cipher systems.

Privacy isn't a marketing tagline for us — it's baked into how every tool is built. There is no server waiting to receive your files. There is no database storing your conversions. There is no account system tracking what you do. The processing runs inside your browser's own protected environment, and the moment you close the tab, everything in memory is wiped clean. You don't have to take our word for it, either. Open your browser's developer tools, switch to the network tab, and use any tool. You won't see a single request sending your data anywhere.

We built ZeroDataUpload because we were frustrated by the status quo. A lawyer shouldn't have to send a client's confidential contract to a third-party server just to remove two pages. A photographer shouldn't have to upload personal wedding photos to some unknown website just to get them into a compatible format. A small business owner shouldn't have to risk their financial spreadsheets on a converter they found through a search ad. These are simple tasks with serious privacy implications, and doing them locally eliminates the risk entirely.

Every tool works on Chrome, Firefox, Safari, and Edge — on desktop, tablet, or phone. There is nothing to install, no browser extension to add, and no account to create. Just open the page and start working. Most tools load instantly. The audio and video converter takes a moment on first use while the processing engine loads, but your browser caches it so subsequent visits are fast.

We also write detailed guides for every tool. Not the kind of help pages that just list features in bullet points — actual in-depth articles that explain how things work, walk through real scenarios, and answer the questions people actually have. Why does a "strong" password need to be at least 12 characters? How do timezones handle daylight saving transitions at the exact switchover moment? What makes AES-256 encryption essentially unbreakable? Why do some favicons look blurry on Android but sharp on iOS? We dig into these topics because understanding the tool makes you better at using it.

The site is maintained by Leena Software Solutions, a company founded with the belief that privacy is not a premium feature — it's a basic right. We don't run ads from third-party networks that track you across the web. We don't collect your email to let you use a tool. We don't put limits on how many files you can process. The tools are free, they're private, and they work. That's the whole deal.

If you run into any issues or have a question about how a specific tool works, the contact page goes directly to the team that builds and maintains these tools. No chatbot, no ticket system, no auto-replies — just real people who know every tool inside and out.

Each tool above includes a detailed feature guide with step-by-step instructions, real-world use cases, and a frequently asked questions section. Click "Learn More" on any card to read the full guide, or hit "Launch" to jump straight into the tool.