ConvertFile

Free Online File Converter

Convert images in your browser. No upload, no account, no waiting.

Drag & drop files here

or Browse Files

Max file size: 10MB · Max 2 files at once

Under 2 seconds
No file uploads
Free, no limits
No account needed

All Tools

Online File Conversion: A Complete Guide

File format incompatibility is one of the most common problems on the internet. You download a WebP image from a website, but your editor only accepts PNG. You screenshot something as a PNG, but the upload form wants JPG. You receive a BMP from a legacy system, but you need it as a modern web format.

ConvertFile solves this by converting images directly in your browser. There is no upload step, no server queue, and no third party handling your files. The HTML5 Canvas API reads your source image, re-encodes it in the target format, and hands you the result. The entire process takes under 2 seconds on most devices.

Why Use a Browser-Based Converter?

Most online converters upload your files to a remote server. That means waiting for the upload to finish, trusting the server operator with your data, and hoping they actually delete your files afterward. Some services keep copies for 24 hours. Others do not specify a retention period at all.

Browser-based conversion eliminates these concerns. Your files never leave your device. The conversion runs on your hardware using the Canvas API, so there is nothing to intercept, nothing to leak, and nothing to forget to delete. You can verify this by opening your browser's network tab during conversion — you will see zero outbound file transfers.

Supported Image Formats

PNG (Portable Network Graphics)

Lossless compression with alpha channel transparency. Ideal for screenshots, logos, UI elements, and graphics with sharp text. Produces larger files than JPG or WebP for photographic content.

JPG / JPEG

Lossy compression optimized for photographs. Produces files 50-80% smaller than PNG with no visible quality loss at 85-90% quality. Does not support transparency. The most universally compatible image format.

WebP

Developed by Google in 2010. Supports both lossy and lossless compression, transparency, and animation. Lossless WebP is 26% smaller than PNG. Lossy WebP is 25-34% smaller than JPG. Supported by all major browsers since 2020.

BMP (Bitmap)

Uncompressed raster format associated with legacy Windows applications. Stores raw pixel data with zero compression, resulting in very large files. A 1920x1080 BMP takes approximately 5.5 MB. Converting to JPG reduces this by up to 95%.

How the Conversion Works

ConvertFile uses the HTML5 Canvas API, a browser-native technology designed for image manipulation. When you drop a file into the converter, the following happens:

1. Your browser reads the file from your local disk into memory. 2. The Canvas API decodes the image pixels into a raw bitmap. 3. The bitmap is re-encoded in your chosen output format with the quality level you selected. 4. The encoded file is offered as a download.

No network requests are made during this process. The conversion is limited only by your device's processing power, which is why it completes in under 2 seconds on modern hardware.

Understanding Image Quality and File Size

Every image format makes a trade-off between file size and visual fidelity. Lossless formats like PNG preserve every pixel exactly, but produce larger files. Lossy formats like JPG discard visual information that the human eye is unlikely to notice, producing much smaller files.

The quality slider in ConvertFile controls this trade-off. At 100%, the output is nearly lossless. At 85-90%, file sizes drop significantly with no visible quality loss for photographs. Below 70%, compression artifacts become noticeable around sharp edges and text. For most use cases, 80-90% is the right setting.

Privacy: Your Files Never Leave Your Device

ConvertFile processes every file locally using your browser's built-in Canvas API. No files are uploaded to any server. No data is collected, stored, or shared. You can verify this by disconnecting from the internet after loading the page — the converter continues to work normally.

This architecture means there is no file retention policy to worry about, no data breach risk from server storage, and no third-party access to your images. Your files exist only in your browser's memory during conversion and are released when you close the tab.

Frequently Asked Questions

Is this file converter really free?

Yes. There are no premium tiers, no watermarks, and no daily limits. The converter runs on your device, so we have no server costs to pass on to you.

Are my files uploaded to a server?

No. All image conversions run in your browser using the HTML5 Canvas API. Your files stay on your device from start to finish. Nothing is transmitted over the network.

What file formats are supported?

ConvertFile currently supports conversions between PNG, JPG (JPEG), WebP, and BMP. PDF tools and document conversion are coming soon.

Is there a file size limit?

Files up to 10MB are supported. Since processing happens in your browser, performance depends on your device. Most images convert in under 2 seconds.

Does the converter work on mobile?

Yes. ConvertFile works on all modern mobile browsers, including Safari on iOS and Chrome on Android. The same local conversion technology works across all devices.

How fast is the conversion?

Most files convert in under 2 seconds. There is no upload or download delay because the conversion runs locally on your device.

Can I convert multiple files at once?

Yes. You can add up to 2 files per batch in the free tier. Each file converts independently, so one failed conversion will not affect the others.

What happens to transparent areas when converting to JPG?

JPG does not support transparency. Any transparent pixels are replaced with a white background during conversion. If you need to keep transparency, convert to PNG or WebP instead.

Do I need to install anything?

No. ConvertFile runs entirely in your browser. There is nothing to install, no plugins to enable, and no extensions to add.