🖼️ Resize Image — Zero Quality Loss

Choose a lossless output format. PNG preserves every pixel exactly with zero compression. WebP Lossless gives identical quality at 20–30% smaller file sizes. If you must use JPEG, never go below 85% quality — most free tools secretly use 75–80% which visibly degrades your image. This tool lets you control JPEG quality directly and uses MozJPEG WASM for ~25% better compression than the browser default.

AVIF uses the AV1 video codec's intra-frame encoder (libaom) — the same technology Squoosh.app uses. At the same perceived visual quality, AVIF files are typically 40–50% smaller than JPEG. AVIF also supports transparency and wider colour gamut. The main limitation is browser support: Chrome 85+, Firefox 93+, Edge 121+. JPEG has universal support including older systems and email clients.

WebP Lossy uses the same libwebp encoder as Chrome's built-in WebP but applies compression — the quality slider controls how much data is discarded. At quality 80, WebP Lossy files are typically 25–35% smaller than JPEG at equivalent visual quality. WebP Lossless stores every pixel exactly — no data is discarded, identical quality to PNG but 20–30% smaller files. Use Lossless for logos, screenshots, and images with text. Use Lossy for photographs.

MozJPEG is Mozilla's improved JPEG encoder that uses more aggressive optimisation passes than the standard encoder. At quality 85, MozJPEG typically produces files 20–30% smaller than the browser's built-in JPEG encoder at the same visual quality. This tool loads MozJPEG as a WebAssembly (WASM) module — the same approach used by Squoosh.app. If WASM fails to load in your browser, the tool silently falls back to the standard browser JPEG encoder with no interruption.

Switch to the Presets tab, select Social Media, and click Instagram Post. The tool instantly sets 1080 × 1080 pixels. For Stories or Reels use Instagram Story which sets 1080 × 1920 pixels. Choose PNG or WebP Lossless as the output format for maximum quality before uploading, since Instagram applies its own compression on top.

A YouTube thumbnail should be 1280 × 720 pixels with a 16:9 aspect ratio. Minimum width is 640 pixels. YouTube recommends JPG, GIF, BMP, or PNG under 2 MB. Use the YouTube Thumbnail preset in the Video & Web category of this tool to apply these exact dimensions with one click, then export as PNG or WebP Lossless for best quality.

This tool automatically detects transparent pixels in your PNG the moment you upload it. If transparency is found, JPEG, WebP Lossy and AVIF are immediately disabled and grayed out — because these formats replace transparent areas with solid white. PNG and WebP Lossless both preserve transparent backgrounds perfectly through the resize. No action is needed from you — the protection is fully automatic.

No. Everything runs entirely in your browser using the HTML5 Canvas API. Your image is never transmitted over the internet, nothing is stored anywhere, and no account is required. The tool works offline after the page loads. This is verifiable: you can disconnect your internet after loading the page and the tool still works perfectly.

The quality slider (1–100) appears when you select JPEG, WebP Lossy, or AVIF — the three lossy formats. Lower values produce smaller files with more visible compression artifacts. Higher values produce larger files with better quality. Each format has its own default: JPEG defaults to 85, WebP Lossy to 80, AVIF to 65 (AVIF at 65 typically looks as good as JPEG at 90+ because of the more efficient codec). PNG and WebP Lossless are always lossless and have no quality slider.

Upload your HEIC file directly. The tool detects the HEIC format automatically, converts it to PNG in your browser using a lightweight library, then applies your resize settings in the same step. The final download is a clean PNG or WebP Lossless file at your chosen dimensions. No separate conversion step or extra app is needed. Works for all iPhone HEIC and HEIF photos.

Downscaling causes minimal quality loss when bicubic interpolation is used — which this tool always applies. Selecting PNG or WebP Lossless output adds zero compression artifacts. JPEG, WebP Lossy, and AVIF add compression on top of the resize — controlled by the quality slider. Upscaling always softens sharpness slightly — this is a fundamental limitation of raster images, not a tool defect.

Input: JPG, JPEG, JFIF, PNG, WebP, GIF (first frame), BMP, AVIF, SVG, HEIC, HEIF — 11 formats total. Output: PNG lossless, WebP Lossless, JPEG (with MozJPEG WASM and quality slider), WebP Lossy (quality slider), AVIF Ultra Small (quality slider, Chrome 85+ / Firefox 93+). HEIC files from iPhone are automatically converted before resizing.

AVIF Ultra Small gives the smallest file size — up to 50% smaller than JPEG at the same visual quality. This uses the browser's native libaom encoder, the same codec as Squoosh.app. AVIF requires Chrome 85+, Firefox 93+, or Edge 121+. If you need broader compatibility, WebP Lossy is the next best option at 25–35% smaller than JPEG with full modern browser support. JPEG with MozJPEG WASM gives ~25% better compression than standard browser JPEG and works everywhere.

Yes. The tool samples your image on upload to detect transparent pixels. If found, JPEG, WebP Lossy and AVIF are automatically disabled — because these formats replace transparency with white. PNG and WebP Lossless both preserve transparent backgrounds perfectly through the entire resize process. The protection is automatic and requires no action from you.

AVIF output requires Chrome 85+, Firefox 93+, or Edge 121+ for encoding. If your browser doesn't support AVIF encoding, the tool automatically falls back to WebP Lossy instead of crashing. AVIF viewing (not just encoding) is supported in all modern browsers. If you need a file that opens on older systems, use JPEG or PNG instead — both have universal support.

Just upload the HEIC file directly — no conversion needed beforehand. The tool detects it automatically, loads a lightweight conversion library in the background, converts the HEIC to PNG in your browser, then applies your resize settings. A confirmation badge shows when conversion is complete. For iPhone photos, AVIF output at quality 65 is an excellent choice — it matches iPhone's own HEIC compression efficiency.

Up to 500 MB. Files above 50 MB are processed using a progressive multi-step resize algorithm — the image is halved in stages toward the target rather than in a single large operation. This prevents browser tab crashes on lower-end devices and produces sharper results. A progress bar and status messages display throughout the process.

AVIF defaults to quality 65, which typically looks as good as JPEG at 90–92% because the AV1 codec is far more efficient. For web thumbnails: quality 55–65. For full-size photos: quality 70–80. For archiving: quality 85+. AVIF at quality 65 is roughly equivalent to WebP Lossy at 80 or JPEG at 90 — all three look nearly identical to the human eye, but AVIF produces the smallest file.

The filename format is: your-original-filename_500x500_a1omads.com.png. Your original filename is always preserved at the start. The dimensions and tool name are appended so you can identify the exact size and source at a glance inside your downloads folder — without renaming anything.

The size bar shows an estimate before download. After you click Resize & Download, the status badge updates with the actual blob size — e.g. "✅ Saved image_800x600_a1omads.com.avif — 42.3 KB actual". The estimate is based on typical compression ratios and will often differ from the actual output, which varies by image content. The actual size is always shown after download.