The Best Free Image Tools Online: Convert, Compress, Resize Without Uploading

If you need to resize a photo before emailing it, convert an HEIC file from an iPhone to JPG, or compress a screenshot so your message board accepts it, you've probably noticed the same thing: most "free" image tools want you to sign up, sit through ads, or — worst of all — upload your file to a stranger's server. For a vacation photo, that's no big deal. For a screenshot of a customer dashboard, a financial document, or a piece of source code, it is.

Uttir's image tools exist to fix that. Every tool runs entirely in your browser using the browser's built-in image and canvas APIs, so your files never leave your device. Here is the full set, grouped by what you might be trying to do.

Convert between formats

Most of the time, the format question is "I have a JPG, I need a PNG (or vice versa)" or "I want a smaller file." Uttir has dedicated tools for every common conversion, and they all preserve quality as much as the destination format allows.

• JPG to PNG — converts JPEG files to lossless PNG. Use this when you need a transparent background or sharper edges, and you don't mind the larger file size. The JPG to PNG converter keeps the original image dimensions.
• PNG to JPG — converts PNG to JPEG with adjustable quality. Use this for photos where you want a much smaller file and don't need transparency. The PNG to JPG converter lets you set the quality and pick a background color for transparent regions.
• WebP Converter — turns JPG or PNG into modern WebP. WebP is 25–35% smaller than JPG at the same quality and is supported in every browser that matters. The WebP converter goes both directions so you can convert WebP back to JPG or PNG for legacy pipelines.
• HEIC to JPG — converts iPhone HEIC photos to JPG entirely in your browser. No upload to a "free converter" that watermarks your file or asks for your email. The HEIC to JPG converter handles both single files and batch conversion.
• Image to Base64 — turns a small image into a data: URL you can paste straight into HTML, CSS, or a README. The Image to Base64 tool is useful for inline icons and avatars where you don't want a separate HTTP request.

Compress without losing quality (or, with losing quality, on purpose)

Compression is one of the most common image tasks, and one of the easiest to do badly. The Image Compressor lets you pick the target format and quality level and shows you the byte savings in real time, before you commit. The compression happens in your browser using canvas re-encoding, so there is no upload and the original is preserved alongside the compressed version.

Two practical tips:

• For photos, JPG at 80% quality is the sweet spot — files shrink by 60–70% with no perceptible loss.
• For screenshots, line art, and anything with sharp edges, PNG is almost always smaller than JPG at the same quality. The PNG to JPG converter is a great way to confirm this for your specific image.

Resize, crop, and prepare for the web

Resizing a large photo down to a reasonable web size is the single biggest speedup you can give a slow-loading page. The Image Resizer lets you set exact pixel dimensions or scale by percentage, with an optional aspect-ratio lock. The Image Cropper pulls a precise pixel region out of any image, useful for thumbnails and profile pictures.

Common web sizes to remember:

• Open Graph / social cards: 1200 × 630 px (the og:image dimensions Google and Facebook use for link previews).
• Twitter / X card: 1200 × 675 px (close enough to 16:9).
• Favicons: 16, 32, 48, and 180 px. The Favicon Generator produces all four from a single source image.

Turn images into PDFs (or vice versa)

The JPG to PDF tool combines a set of JPG or PNG images into a single PDF, one page per image. Useful for sending a quick photo album to someone who doesn't have a photo viewer, or for archiving receipts and screenshots as a single document. The reverse direction (PDF page → image) is one of the PDF tools.

Use generated images directly in your projects

For mockups and prototypes, the Placeholder Image Generator outputs inline SVG at any size with custom text and colors. Pure SVG, no server request, scales infinitely. If you need a quick favicon from a logo or photograph, the Favicon Generator produces a full multi-size ICO-ready set in one click.

How to pick a format (the 30-second version)

If you remember nothing else, remember this:

• Photo, no transparency → JPG. 60–80% quality. Use WebP if you can.
• Screenshot, line art, transparency → PNG. Lossless, perfect edges.
• Logo or icon that needs to scale → SVG.
• iPhone photo → convert HEIC to JPG first, then compress.

For a longer discussion with the trade-offs spelled out, the JPEG vs PNG vs WebP vs AVIF vs SVG guide goes deep on when to use which.

Why browser-based, not upload-based

An "upload-based" image tool sends your file to a server, processes it, and sends it back. The latency is fine, but you've just handed your photo to a stranger. The latency for a browser-based tool is zero, and the stranger never sees anything. You can verify this with DevTools → Network tab: the only requests are the initial page load and your ad impression. Open the Network tab, use any of these tools, and watch.

Bookmark the ones you use most, share the rest with a coworker, and remember: the best image tool is the one that doesn't ask for your email.