What is StackConvert? Your Complete Guide to Free Online File Conversion Tools

Introduction to StackConvert

StackConvert started as a simple idea: why do you need five different websites just to convert an image, merge a PDF, and format some JSON? So we built one site that does all of it.

There are over 20 tools on the site now, and they all run directly in your browser. That means your files never get uploaded anywhere. They stay on your device the whole time, which matters a lot if you are working with anything sensitive or just do not want your stuff sitting on someone else's server.

No accounts, no downloads, no paywalls. You just open the tool you need and use it.

Image Conversion Tools

The image converter is probably the most-used tool on the site. It handles the formats you would expect - JPEG, PNG, WebP, GIF - but also supports AVIF, HEIC (the format iPhones use), TIFF, BMP, ICO, and SVG. You can convert between any of them.

Beyond just changing formats, you can adjust compression quality with a real-time preview, resize images by width, height, or percentage, strip EXIF metadata for privacy, and process multiple images at once. If you are optimizing for the web, there is also an option to create progressive JPEGs, which load faster in browsers.

Other Image Tools

There are a few more image-related tools beyond the main converter:

• Image Base64 Encoder/Decoder - useful for web developers who need to embed images directly in HTML or CSS
• Image Metadata Extractor - pulls out EXIF data and file properties from any image
• Image Aspect Ratio Finder - tells you the exact dimensions and aspect ratio of an image, which is handy for responsive design or social media sizing
• Images to PDF - combines multiple images into a single PDF with automatic page sizing. Good for bundling receipts, scanned pages, or photo collections

PDF Management Tools

PDFs are one of those things everyone deals with but nobody wants to pay for software to manage. StackConvert has six PDF tools that cover the most common tasks.

PDF Merge lets you combine multiple PDFs into one file. You drag and drop the files in, reorder them however you want, and merge. It shows you thumbnail previews so you can see what you are working with before you combine anything.

PDF Split does the opposite - you take a big PDF and pull out the pages you need. You can specify page ranges like "1-3,5,7-9", split it into equal chunks, or extract every page as its own file. There is a preview so you can see what each page looks like.

PDF Compress is useful when you need to email a PDF that is too large. You pick a compression level (low, medium, or high), and it shrinks the file size while trying to keep the quality reasonable. You can also strip metadata to reduce it further.

PDF Reorder lets you rearrange pages within a PDF by dragging them around. You can also rotate individual pages or delete ones you do not need.

Then there is Word to PDF and PDF to Word for converting between those two formats. Both try to preserve the original formatting, fonts, and layout as closely as possible. Like everything else on the site, the conversion happens in your browser.

JSON Utilities

These tools are mainly for developers, but anyone who works with data files will find them useful.

The JSON Viewer and Formatter takes messy or minified JSON and makes it readable. It shows you a color-coded tree structure you can expand and collapse, validates the syntax in real time, and gives you stats like object counts and array lengths. The JSON Editor goes a step further - you can actually edit JSON directly with error highlighting, bracket matching, and undo/redo.

The JSON Diff Tool is one that developers tend to use a lot. You paste in two JSON files, and it shows them side by side with the differences highlighted. It handles deeply nested objects and arrays, which is where most diff tools start to struggle.

There are also converters for JSON to YAML and YAML to JSON. Both convert in real time as you type or paste, validate your input, and let you copy or download the result. If you work with config files in different formats, these save a lot of manual reformatting.

QR Code Generator

The QR code generator supports more than just URLs. You can create codes for plain text, email addresses (with a pre-filled subject and body), phone numbers, SMS messages, WiFi credentials, vCards, and GPS locations. It covers most of the situations where you would actually want a QR code.

On the design side, you can change the colors, add gradients, embed your own logo in the center, and choose from different frame styles. The output goes up to 2048x2048 pixels, and you can adjust the error correction level depending on whether the code needs to work when partially covered or printed small. There is a real-time preview that updates as you tweak things, so you can see exactly what the final code will look like before you download it.

Additional Utility Tools

These are the smaller tools that round out the site. They are not as flashy as the image or PDF tools, but they come in handy more often than you would think.

The Hash Generator creates bcrypt hashes for passwords and lets you verify existing hashes against plain text. You can configure the salt rounds for different security levels. It is a quick way to generate hashes without writing code or spinning up a terminal.

The ZIP Creator bundles multiple files into a ZIP archive right in your browser. You drag files in, adjust the compression level, and download the archive. Useful when you need to send a handful of files to someone.

For time-related tasks, there is a Time Converter that handles 100+ global timezones with live tracking, and a Unix Timestamp Converter that goes both ways between epoch timestamps and human-readable dates. The timestamp tool also shows relative time (like "3 years ago") which is a nice touch when you are debugging logs.

Privacy and Security

This is the part we care about the most. When you use an online converter, the natural question is: where are my files going? With most tools, the answer is "to their server." With StackConvert, the answer is nowhere. Everything runs in your browser using JavaScript, so your files literally never leave your device.

There is no account to create, so there is no personal data to collect. There is no server upload, so there is nothing to breach or leak. It is about as private as an online tool can get. You can read the full details in our Privacy Policy if you want the specifics.

Why Choose StackConvert?

There are tons of file converters online, so here is the honest case for this one.

First, it is genuinely free. Not "free with watermarks" or "free for 3 conversions a day." There is no premium tier hiding behind the free tools. You get the same features whether it is your first visit or your hundredth.

Second, everything is in one place. Instead of bookmarking a different site for images, another for PDFs, and another for JSON, you can just use StackConvert for all of it. There are over 20 tools, and they all work the same way: drop your file in, get the result out.

Third, it is fast. Since the processing happens in your browser instead of on a server, there is no upload time and no waiting in a queue. The conversion starts immediately. It works on phones and tablets too, not just desktops.

And fourth, there are no watermarks, no daily limits, and no registration. You do not even need to give an email address. Just use the tools.

Getting Started

There is not much to explain here. Go to StackConvert.com, pick the tool you need, drag your file in, and download the result. That is the whole process. No account, no setup, no learning curve.

If you are not sure which tool to start with, the image converter and PDF merge are the two most popular ones. But honestly, just bookmark the site and use whatever tool you need when the moment comes. That is how most people end up using it.