Image Resizer

Image Resizer – Exact Pixels, Percentage, or Presets in Your Browser

Resize images to exact pixel dimensions, by percentage (1 to 800%), or with one-click social presets (Instagram post 1080 x 1080, Story 1080 x 1920, Facebook link 1200 x 630, YouTube thumbnail 1280 x 720, X post 1600 x 900, LinkedIn banner 1584 x 396). Change output to JPG, PNG, WebP, AVIF, GIF, BMP, ICO, TIFF, PDF, or SVG in the same pass, or keep the original format. AVIF encodes in every browser (native where supported, automatic high-quality fallback otherwise). Everything runs locally with Canvas: up to 20 images per batch, 10 MB each, no upload, no watermark. Each image gets a single card that updates in place, a fullscreen progress overlay shows the percentage while resizing, and a live counter totals the batch savings. Inputs accepted: JPG/JPEG, PNG, WebP, AVIF, GIF (first frame), BMP, ICO, SVG, TIFF, and iPhone HEIC/HEIF.

How to Resize Images

1. Add images: Drop files onto the dashed area, click it, or press Browse files. You can also paste an image from the clipboard. Each row shows a thumbnail, original dimensions, file size, and the projected output size, which updates live as you change settings.
2. Pick a mode: Exact pixels (enter Width and Height), Percentage (slider plus 25/50/75/100/150/200% shortcuts), or Preset size (grouped dropdown for Instagram, social/video, and web).
3. Keep proportions: Lock aspect ratio is on by default, so each image fits inside the entered box without stretching. Do not enlarge small images is also on, so pictures smaller than the target keep their original size instead of turning soft.
4. Output and quality: Choose Keep original, JPG, PNG, WebP, AVIF, GIF, BMP, ICO, TIFF, PDF, or SVG. GIF, BMP, ICO, TIFF, PDF, and SVG all encode directly in the browser; only HEIC/HEIF kept as-is falls back to PNG with a visible note. Drag Quality (default 85%) for JPG, WebP, and AVIF; the slider hides for the other formats because they are lossless or fixed-quality.
5. Resize and download: Press Resize images. A fullscreen overlay with a spinner and percentage shows progress, then each image card updates in place: new file name, old dimensions to new dimensions, old size to new size, and a green Saved or red Larger badge. The top counter totals the batch (3 images – 1.38MB to 33KB – Saved 98%). If a result is larger than its original, the card explains why and suggests a fix, with a one-click Re-resize at 80% for JPG, WebP, and AVIF. Download files one by one or all at once with Download ZIP (enabled with 1 or more results). File names carry the new size, for example photo-1920×1080.jpg.

Real Examples

• Blog photo: A 4000 x 3000 camera JPG, Exact pixels 1920 wide with aspect lock, JPG at 85%. Result: 1920 x 1440, roughly a third of the original bytes, downloaded as photo-1920×1440.jpg.
• Batch thumbnails: Six PNG screenshots, Percentage 50%. Each keeps its own ratio (for example 1600 x 900 becomes 800 x 450), then Download all (ZIP) saves resized-images.zip.
• Social post: A portrait photo, Preset size Instagram Square post 1080 x 1080. With aspect lock the photo fits inside 1080 x 1080 (for example 810 x 1080) without cropping or stretching.

Inputs, Settings, and Result

• Inputs: JPG/JPEG, PNG, WebP, AVIF, GIF, BMP, ICO, SVG, TIFF, HEIC/HEIF. Max 20 files, 10 MB each, max side 16000 px. HEIC decodes via heic2any 0.0.4, TIFF via UTIF 3.1.0, ZIP via jszip 3.10.1, AVIF fallback encodes via @jsquash/avif 2.1.1, each lazy-loaded only when needed. Animated GIF input saves as a still image (first frame).
• Modes: Exact pixels (1 to 16000 per side), Percentage (1 to 800, slider covers 1 to 200), Preset size (11 presets in 3 groups). Aspect lock fits inside the box; with lock off, exact values stretch to the entered size. No-enlarge caps the scale at 100%.
• Quality: 1 to 100, default 85, live Quality 85% label. Applies to JPG, WebP, AVIF only; the slider hides for PNG, GIF, BMP, ICO, TIFF, PDF, and SVG.
• Result cards: One card per image with thumbnail preview (TIFF results show a PNG preview), new file name with dimensions, dimension change, size change with a green Saved or red Larger badge, per-file Download, and per-file Remove. A Download ZIP button in the top bar is enabled with 1 or more results. If a result ends up larger than its original, the card shows a tailored hint: PNG suggests JPG/WebP, BMP suggests JPG/PNG/WebP, ICO and TIFF suggest PNG, GIF suggests fewer colors or PNG, PDF and SVG suggest JPG/PNG, and JPG/WebP/AVIF get a one-click Re-resize at 80% button.
• Privacy: Files never leave the device. Re-encoding removes metadata (EXIF, including location data). Blob URLs are revoked after remove, clear, or re-resize to free memory.

FAQ – Quick Answers

How do I resize without stretching the photo?

Leave Lock aspect ratio on and enter only the side you care about; the other side follows automatically (based on the first image) and every image in a batch keeps its own ratio at resize time.

Will small images get bigger?

No, as long as Do not enlarge small images stays checked (the default). Uncheck it only when you deliberately want to upscale.

Which format should I pick?

JPG at 80 to 85% for photos, PNG for logos or anything needing transparency, WebP for smaller web files with transparency support, AVIF for the smallest files in any browser (native encoding where supported, automatic fallback otherwise). GIF for simple animations-as-stills and retro graphics, BMP for raw bitmaps, ICO for favicons, TIFF for print and archival quality, PDF to wrap an image as a document page, SVG to embed it as a scalable vector wrapper.

What if the resized file is larger than the original?

Sometimes a re-encoded file outgrows its source – for example PNG output of an optimized photo, or AVIF at high quality. The card turns the badge red and shows a tailored hint for that format, so you know exactly what to try next. For JPG, WebP, and AVIF there is also a one-click Re-resize at 80% button that re-runs the batch at lower quality.

What happens to quality when I downscale?

Downscaling uses stepped drawing (halving toward the target with high smoothing), which keeps detail cleaner than a single jump. Upscaling cannot invent detail, so start from the largest original you have.

Limits and Error Handling

• More than 20 files shows You can resize up to 20 images at once. Remove some files to continue.
• Files over 10 MB show Each image must be 10 MB or smaller.
• Other file types show That file type is not supported. Use JPG, PNG, WebP, AVIF, GIF, BMP, ICO, SVG, TIFF, or HEIC.
• Unreadable files show That image could not be read. The file may be corrupt. HEIC and TIFF have their own specific messages.
• Empty width, height, or percentage shows which field is wrong and the valid range. Resizing with no images shows Add at least one image first.