Free PNG to WebP Converter

How ConvertUnlimited works

ConvertUnlimited is a browser-native utility site for common image, PDF, and developer tasks. For supported image workflows, the selected file is read by the browser, decoded with browser APIs such as Canvas, re-encoded in the selected output format, and offered back as a download from the same tab.

This local-processing model means ConvertUnlimited does not provide a server-side upload endpoint for supported image conversion flows. It does not mean every browser can process every file: very large images, unsupported formats, limited memory, or browser encoder differences can still affect results.

Conversion uses your computer's CPU and memory. Typical laptop workflows can handle moderate batches of phone-camera images, while hundreds of high-megapixel files can increase memory pressure and slow the browser tab. Start with roughly 50 images per batch and adjust based on device performance. See Tips for big batches for larger jobs.

Start with the tools index when you need a specific workflow, or read how local browser processing works before using the site with sensitive files.

Image format guide

Image formats differ by file size, quality behavior, transparency support, and compatibility. The notes below summarize the formats ConvertUnlimited reads and writes, and when each format is appropriate.

WebP

A modern image format developed by Google. At comparable visual quality, WebP files are often smaller than JPEG and PNG, and WebP supports transparency. Choose WebP for modern web delivery when the publishing system and target browsers support it.

JPEG

A broadly supported photo format. JPEG is lossy, does not support transparency, and remains compatible with most publishing systems, email clients, social platforms, printers, and older software. Choose JPEG when compatibility is the main requirement.

PNG

A lossless format with transparency support. PNG is suitable for screenshots, logos, icons, and graphics with sharp edges or solid-colour regions. The tradeoff is file size: photographic PNG files are often much larger than equivalent JPEG or WebP outputs.

GIF

A legacy bitmap format with basic animation support and a 256-colour palette. GIF can be inefficient for photos and complex graphics. ConvertUnlimited reads GIF files and converts the first frame; animated GIF output is not preserved.

SVG

A vector format based on XML drawing commands. ConvertUnlimited reads SVG files and rasterizes them at their natural dimensions. After rasterization, the output behaves like a pixel image, so convert SVG only when a raster output is required.

BMP

An uncompressed bitmap format. BMP files are usually large relative to their visual content. For web or sharing workflows, convert BMP to WebP, JPEG, or PNG unless the target system specifically requires BMP.

Choosing the right quality

The quality dropdown only applies to lossy formats (WebP and JPEG). PNG is lossless, so the dropdown is automatically disabled when PNG is selected. The four presets translate roughly to:

Original (1.0). Highest available encoder quality. Output may still differ from the source because the browser writes a new file.

High (0.9). High visual quality for photos and prominent web images, with moderate size reduction in many cases.

Recommended (0.75). Balanced web output for articles, product images, and social media assets.

Compact (0.5). Stronger compression for thumbnails, image grids, and bandwidth-constrained sharing. Text-heavy or high-contrast images may show artifacts sooner.

Tips for big batches

Use smaller batches when converting many large files:

Batch size. Start with about 50 images at a time. Larger batches may work, but browser memory allocation can briefly make the tab unresponsive.

RAM matters more than CPU. A 12-megapixel photo can require roughly 50 MB of memory after decoding. A batch of 100 such photos can temporarily require several gigabytes of memory. Closing other tabs can help on low-memory devices.

Mobile. Phones and tablets have less RAM and stricter background limits. Stick to smaller batches (10–20 images) on mobile devices.

ZIP downloads. After conversion, the "Download all as ZIP" button bundles outputs into one archive for easier batch download.

What is PNG?

PNG (Portable Network Graphics) is a lossless format that supports transparency and is ideal for graphics, logos, and screenshots.

What is WebP?

WebP reduces image file sizes while preserving quality. It supports both lossy and lossless compression and transparency.

Deep Dive: Read our full PNG vs WebP comparison guide.

Frequently Asked Questions

Is the conversion local?

Yes. The conversion uses browser-native image processing. File contents are not intentionally uploaded by this tool.

Can I convert multiple PNG files at once?

Yes, you can drag and drop hundreds of PNG files and convert them all to WebP in one click.

What is the limit?

There is no account-level file count limit. Practical limits depend on your device memory and browser capability.

Which version should I use for sensitive files?

Privacy

Privacy build: This build removes ads, analytics, remote fonts, runtime CDN scripts, and file-operation telemetry. Selected files are processed in the browser using local JavaScript and browser APIs.

Selected images. ConvertUnlimited converts images entirely inside your browser. Selected file contents are processed locally in your browser for this supported workflow. ConvertUnlimited does not provide a server-side upload endpoint for this processing flow. File contents are not intentionally uploaded by this tool.

Contact. For privacy questions, reach out via the project's GitHub.