Free PNG Tools — Compress, Resize and Convert in Your Browser

Which one you actually want — and why one tool beats the obvious alternative — group by group.

Converting between formats

PNG → JPG for smaller web files when you don't need transparency. PNG → WebP for the best size / quality / alpha trade-off on the modern web. JPG / WebP → PNG to round-trip back. SVG → PNG rasterises vector art at the resolution you pick. PNG → PDF bundles a stack of images into a single multi-page document, and PNG → ICO builds a multi-resolution Windows favicon from one square PNG.

For the awkward formats: AVIF → PNG and ICO → PNG open files half your software can't, and BMP → PNG shrinks raw bitmaps by 5–20× losslessly. Going the other way, PNG → BMP and PNG → TIFF write real 24/32-bit BMP and uncompressed RGB/RGBA TIFF byte by byte for legacy tools and print workflows, and PNG → SVG either traces to genuine vector shapes or wraps the bitmap, whichever you need. For developers there's PNG → byte array in C, Rust, Python, Go, Java or JS, PNG → BlurHash with a decoded preview, and PNG → ASCII art for the fun of it.

Optimizing

Compress re-encodes at a quality you pick — typical 50–70% size reduction by going lossy WebP. Resize by pixels, percent, or fit-to-width / fit-to-height with aspect ratio preserved. Crop with numeric XYWH, batch-friendly. Auto-trim automatically removes transparent edges — perfect after compositing in another tool.

When a form imposes a hard limit, Target file size binary-searches quality to land just under the KB figure you type. Reduce colors quantises with optional Floyd–Steinberg dithering and shows the before/after bytes, and Remove metadata strips EXIF, timestamps and colour profiles at the chunk level while passing the pixels through untouched. Thumbnail set and Social media sizes produce whole families of sizes in one pass, Change DPI writes a real pHYs tag for print, and Upscale enlarges with stepped resampling — with Pixel-art upscale for sprites, where blurring is the last thing you want.

Transforming and composing

Rotate / flip for sideways phone photos or mirroring. Background swaps transparency for a solid colour, or removes a near-pure colour from PNG (chroma-key style). Round corners adds rounded corners with transparency. Border / frame adds a coloured frame at any width. Pixelate / blur redacts faces or sensitive areas. Watermark stamps text. Sprite sheet packs N images into a grid; Split tiles goes the other way.

Crop to ratio takes the largest 16:9 or 1:1 rectangle that fits, anchored where you choose — no stretching. Add padding adds margin per edge, and Polygon crop masks to a hexagon, triangle or anything up to twelve sides. Join images stitches a strip or a stack, Overlay images composites two files with any of sixteen blend modes, and Seamless pattern makes a texture tile without visible seams. Drop shadow and Add outline both follow the real silhouette of a cut-out rather than its bounding box.

Effects and colour

The adjustment set covers brightness, contrast, saturation, gamma — which lifts shadows without clipping highlights, unlike brightness — hue rotate for instant colourways, and colour temperature on a real Kelvin scale. For treatments: gradient map recolours by brightness and is the single strongest one-step grade, vignette, emboss, edge detect, posterize, halftone for the newspaper dot screen, dither with Floyd–Steinberg, Atkinson or ordered Bayer, and motion blur at any angle.

On the analysis side, Dominant colours extracts a palette ranked by how much of the image each colour covers, Average colour reduces everything to one hex (in both sRGB and linear light, which differ more than you'd expect), and Histogram shows per-channel levels with clipping percentages.

Generating from nothing

Solid color generates a flat-colour PNG at any dimensions. Gradient does linear, radial and conic with up to three stops. Text to PNG renders type on transparency with the canvas auto-sized to fit. Placeholder writes the dimensions onto a grey box so you own the asset instead of hotlinking a service. Checkerboard, noise texture and a blank transparent PNG cover the rest. Favicon kit produces a full set (.ico, multiple PNGs, web manifest) from one square source, and OG image builds a 1200×630 social card with title text.

Inspecting

Image viewer previews dropped files at full size. Inspector reads dimensions, megapixels, alpha, file size, and EXIF when present. Color picker grabs the hex of any pixel and extracts a small palette. Image diff compares two images and highlights pixel differences — handy for QA / regression.

Going deeper into the file itself: Chunk viewer lists every PNG chunk with its size, offset, CRC status and decoded meaning — which is how you find out why a "simple" icon is 40 KB. PNG validator runs the specification's structural checks and tells you specifically what's wrong with a file that won't open. Transparency checker answers whether a background is genuinely transparent or merely white, and Find duplicates uses a two-axis perceptual hash to catch resized and re-encoded copies of the same picture.

Newest additions

PNG to 8-bit indexed is the one worth knowing about: it writes a real palette PNG with a PLTE chunk and one index per pixel — or fewer than eight bits per pixel when the palette is small enough — which is where the size saving that ordinary "compression" cannot reach actually comes from. On screenshots and flat illustration it routinely cuts 60–80%. HEIC to PNG opens the photos your iPhone insists on producing, using a WebAssembly decoder that only downloads if your browser needs it. PNG to ICNS builds a macOS app icon from one square image, and PNG to TGA and PNG to PPM cover the two formats that game and systems-programming pipelines still ask for.

Three new geometric warps: Perspective solves a real homography so parallel lines converge the way they do in a photograph — which a skew cannot do — while Fisheye adds or removes barrel distortion and Swirl twists the frame around its centre. On the painterly side, Oil painting is a genuine Kuwahara filter that flattens interiors while leaving edges alone, Pencil sketch does the colour-dodge line extraction properly, and Pixel sort, Kaleidoscope, Glow and Chromatic aberration round out the effects.

For colour work, Apply a .cube LUT grades a batch with the same LUT your video software uses, Auto levels fixes a flat histogram three different ways, and Colour splash keeps one hue and drains the rest. Plus Contact sheet for an indexed thumbnail grid, Apply an alpha mask and Feather edges for compositing, Add a caption, Initials avatar, Denoise, braille art, and Perceptual hash for aHash, dHash and pHash values with the Hamming distance between every pair.

What they have in common

Three ways in. Drop files on the page — anywhere on it, not just the dashed box — click to open a file picker, or just press Ctrl/⌘+V to use whatever image is on your clipboard. ⌘+Enter runs the tool, and pressing / anywhere jumps to the tool finder at the top of the page — which is the fastest way through 161 of them.

Everything runs in your browser. The images you drop never leave your machine — there is no server component handling data. No upload size cap beyond your browser's memory (typically 500 MB to 1 GB total per batch), no account required, and nothing for me to leak. See the privacy policy for the longer version.

Batch mode by default. Every tool accepts more than one image at a time and processes them sequentially. You drop a folder of screenshots, choose a target format / size / crop / watermark, and get a folder of processed images back without scripting anything. More than one result gets a single Download all (.zip) button, so a batch of forty is one click rather than forty.

Free to use, with no warranty. Read the terms of use before relying on the output for anything load-bearing. Bug reports and feature requests are always welcome — drop me a line.