Image Tools
Every Image Tools tool on Toolz.dev: 6 free utilities that run entirely in your browser. No signup, no uploads, no downloads.
These six tools change an image file rather than the picture in it: its dimensions, its format, its file size, its metadata or its palette. All of them decode the image in your browser, work on the pixels there, and hand back a new file. Nothing is uploaded, which for photographs matters more than it does for most file types, because a photograph from a phone carries the time and often the exact coordinates where it was taken.
The order of operations is worth getting right. Resize first, because most oversized files are oversized in pixels rather than in encoding, and a 4000px photograph shown in a 800px column is wasting seven eighths of its data. Then compress to trade a little quality for a lot of bytes, or convert the format if the destination supports something more efficient. Run the EXIF remover last if the image is going anywhere public.
Which image tool for which problem
| Problem | Tool | What it changes |
|---|---|---|
| Image is larger than it displays | Image Resize | Pixel dimensions, keeping the aspect ratio |
| File is too heavy for the page | Image Compress | Encoding quality, not dimensions |
| Wrong format for the destination | Image Format Converter | Container and encoder: PNG, JPG, WebP |
| Photo carries location and device data | EXIF Remover | Strips metadata without touching the pixels |
| Subject needs cutting out of a flat background | Background Remover | Makes matching pixels transparent |
| Image needs a print or retro treatment | Image Dither | Reduces to a palette with six dithering modes |
Metadata is the one that is worth doing first
A photograph taken on a phone typically carries EXIF metadata recording the camera model, its settings, the exact time, and unless location services were off, the GPS coordinates of where the shutter opened. Posting that file publicly publishes all of it. Most large social platforms strip metadata on upload, but a file attached to an email, uploaded to a forum, sent through a messenger that preserves originals, or hosted on your own site keeps everything.
How the stripping is done matters. The obvious method is to draw the image to a canvas and re-encode it, which does remove the metadata and also re-compresses every pixel, so a JPEG loses quality for a metadata edit. The EXIF remover instead removes the metadata segments from the container and leaves the compressed image data byte for byte identical, so the picture is unchanged. It also shows you what was in the file before you strip it, which is usually more interesting than people expect.
What resizing and recompressing actually cost
JPEG and WebP are lossy: they discard information the eye is poor at noticing, and that information does not come back. Every save is a fresh loss, so an image opened, edited and saved repeatedly degrades visibly, and converting a JPEG to PNG afterwards preserves the damage rather than repairing it. PNG is lossless and the right choice for screenshots, line art, logos and anything with sharp edges or transparency; for photographs it produces files several times larger than a JPEG nobody would tell apart.
WebP is the current default for the web, typically 25 to 35 percent smaller than JPEG at the same visual quality, with transparency support and universal browser support since 2020. The one thing to be careful about with the format converter is direction: converting to a lossless format never improves a lossy source, and converting a PNG screenshot to JPEG introduces ringing around text that no quality setting removes cleanly.
The two tools that are about the look
The background remover works by colour similarity, not by subject detection. On a logo, a product on a plain sweep or a scanned signature it does exactly what is wanted; on a portrait with a busy or gradient background it cannot separate the subject at any tolerance, because there is no single background colour to match. Even on flat backgrounds, edges are the hard part: anti-aliased pixels around the subject are blends of subject and background, so a faint halo can survive, and hair, fur and motion blur are where that shows.
The dither tool goes the other way, reducing an image to a small palette on purpose. Its six modes are genuinely different techniques rather than presets: Floyd-Steinberg distributes the full quantisation error across four neighbours and is the most photographically faithful; Atkinson, written by Bill Atkinson for the original Macintosh, passes on only three quarters of the error, which blows out highlights into the high-contrast MacPaint look; Bayer 4x4 uses an ordered threshold matrix for a regular crosshatch; and the halftone mode samples along a rotated lattice the way a real halftone screen is angled on press.
Frequently asked questions
- Are my images uploaded to a server?
- No. Every image tool here decodes the file in your browser, works on the pixels on your device, and produces the new file locally. This is the reason to prefer a client-side tool for photographs specifically: a phone photo usually carries the time and GPS coordinates of where it was taken, and uploading it to a web service to remove that data hands over the data first.
- Does removing EXIF data reduce image quality?
- Not here. The metadata segments are removed from the file container and the compressed image data is left byte for byte identical, so the picture is unchanged. The common alternative method, redrawing the image on a canvas and saving it again, does strip metadata but re-encodes every pixel, which costs quality on a JPEG for no reason.
- Does converting a JPEG to PNG improve its quality?
- No. JPEG discards information when it saves, and converting to a lossless format afterwards preserves exactly what survived rather than restoring what was lost. PNG is the right format for screenshots, logos and line art, where its lossless compression and transparency matter; for photographs it produces a much larger file with no visible gain.
- Should I resize or compress an image first?
- Resize first. Most oversized files are oversized in pixels, and an image displayed at 800px wide gains nothing from being 4000px. Reducing the dimensions removes the majority of the weight before any quality is traded, and compression then works on a file where every remaining pixel is one the page will actually show.
- Why does background removal leave a halo around my subject?
- Because the edge pixels are blends of the subject and the background. Anti-aliasing mixes the two colours along every boundary, so removing everything that matches the background exactly leaves a rim that is partly background, and raising the tolerance to catch it starts eating the subject. Hair, fur and motion blur are the worst cases, and the tool works best on flat backgrounds.
- Which image format should I use on a website?
- WebP for most images, since it is typically 25 to 35 percent smaller than JPEG at matching quality, supports transparency, and has been supported by every major browser since 2020. Keep PNG for screenshots, logos and anything with sharp edges or transparency where lossless matters, and JPEG only where a consumer needs the most widely accepted format.