Zero Snippet

Image resizer online — scale by percentage or exact pixels without uploading to a server

Use this free online image resizer to change width and height for PNG, JPEG, WebP, and GIF files entirely in your browser. Choose percentage scaling for proportional thumbnails or exact pixel dimensions with an optional aspect ratio lock so screenshots and product photos do not stretch. Export PNG, JPEG, or WebP, tune JPEG quality, then download the file or copy the image to the clipboard where your browser allows it. Processing uses the HTML Canvas API—nothing is sent to our infrastructure. For smaller byte sizes after resizing, follow up with the image compressor; for format changes use the image format converter; for data URIs try the image to Base64 converter. Browse every utility in File and Data Tools.

Drag and drop an image here, or use .

Load a PNG, JPEG, WebP, or GIF to resize by percentage or exact pixel dimensions. Everything stays in your browser.

JPEG export may replace transparent regions with a solid background. Animated GIFs collapse to a single frame. For EXIF and camera metadata on the original file, use the image metadata viewer in the catalog.

Why resize images in the browser for SEO, email, and social assets

Page speed signals and Core Web Vitals reward appropriately sized raster assets. Uploading a 4000px-wide hero into a CMS that displays it at 1200px wastes bytes and decoding work. A quick resize photo online step—paired with compression—aligns pixel dimensions to real layout breakpoints. Marketing teams also need resize image for email and ad specs without installing desktop suites. This tool targets those workflows while keeping files on-device, which matters for NDAs, unreleased products, and support screenshots that include customer data.

People often search for change image dimensions, scale image by percentage, or shrink PNG for website. Percentage mode answers “make this half size” requests; pixel mode answers strict platform requirements such as fixed avatar or marketplace image slots. When you only need to inspect camera EXIF or GPS fields instead of changing pixels, open the image metadata viewer.

How to use this image resizer (step by step)

  1. Click Upload image (with the upload icon) or drag a file into the dashed drop zone. Supported inputs are typical raster types your browser can decode—PNG, JPEG, WebP, and GIF work well.
  2. Review the original preview and native width × height. Pick Percentage and move the slider (1–400%) for uniform scaling, or Exact pixels to type target width and height.
  3. In pixel mode, keep Lock aspect ratio checked to avoid stretching; uncheck only when you intentionally need non-uniform scaling.
  4. Choose an output format. Use PNG or WebP when you need transparency; use JPEG for photos where alpha is unnecessary and adjust JPEG quality to balance size and artifacts.
  5. Confirm the live preview and output dimensions, then click Download resized or Copy image (copy icon). If clipboard copy is blocked, download the file and attach it manually.

Pixel math, aspect ratio, and quality trade-offs

Uniform scaling multiplies both axes by the same factor, preserving geometry. When you unlock aspect ratio and set different width and height multipliers, the canvas stretches content—useful for rare layout corrections but usually undesirable for photography. JPEG is lossy: each re-encode can introduce additional artifacts, so prefer exporting JPEG from the original once when possible, or use PNG/WebP for intermediate steps. After resizing, run the image compressor when you need the smallest acceptable file for production.

Privacy, GIF animation, and SVG

Because decoding and drawing happen locally, you can resize internal UI captures without exposing them to a third-party API. Animated GIFs decode to a single raster frame on canvas, so motion is not preserved; treat this page as a static image resizer. SVG is vector markup—this workflow targets bitmaps. For SVG cleanup and size reduction, use the SVG optimizer.

Related file and data tools

Explore the full file and data tools section. Highlights:

  • CSV Viewer & Editor — Open CSV as a sortable, filterable table, tweak cells, and export without a spreadsheet app.
  • CSV Deduplicator — Remove duplicate rows by chosen columns to clean mailing lists and product feeds.
  • CSV to SQL Converter — Generate INSERT statements from a CSV for quick database seeding and migrations.
  • Image to Base64 Converter — Encode images to Base64 data URIs for embedding in HTML, CSS, or API payloads.
  • Image Compressor — Shrink JPG and PNG with quality control and before/after size stats for faster pages.
  • Image Format Converter — Convert between JPG, PNG, and WebP locally to match CMS, email, and performance needs.
  • Image Metadata Viewer — Inspect EXIF: camera, lens, GPS, dimensions, and exposure—great for photographers and forensics.
  • File Hash Checker — Compute MD5, SHA-1, and SHA-256 hashes of uploads to verify downloads and integrity.
  • SVG Optimizer — Minify and clean SVG markup to cut file size for icons, illustrations, and inline graphics.

Working with CSV exports or feeds after batch-processing images? Try the CSV viewer and editor or CSV deduplicator when cleaning product catalogs.

Frequently asked questions

Are my images uploaded to your server?
No. Files are read with the File API and decoded with an HTML canvas in your browser tab. Resized pixels never leave your device unless you explicitly download them or copy them to the clipboard yourself.
What is the difference between pixel mode and percentage mode?
Percentage mode scales width and height together from the original dimensions—for example 50% halves both sides. Pixel mode sets exact output width and height; when aspect ratio lock is on, changing one dimension recalculates the other so the image is not stretched.
Will resizing always keep my PNG transparency?
PNG and WebP outputs preserve alpha when the browser supports it. If you export to JPEG, transparent areas are typically filled with black or another matte color because JPEG has no alpha channel. Use PNG or WebP when you need transparency.
Why did my animated GIF become a still image?
Canvas-based resizing draws a single frame. Animated GIFs are decoded as one raster snapshot, so motion and timing are lost. For animated assets, use dedicated GIF editors or server-side tooling; this page is aimed at static photos, screenshots, and UI graphics.
Is there a maximum width or height?
Browsers impose memory limits on canvas dimensions. This tool warns when an edge exceeds 8,192 pixels or when width times height is extremely large. If you hit a limit, reduce percentage or pixel targets, or preprocess the file with desktop software.
How do I get smaller file sizes after resizing?
Fewer pixels usually mean smaller files, but format and compression still matter. After resizing, try the image compressor for JPG and PNG, convert formats with the image format converter, or embed small assets with the image to Base64 converter when your stack expects data URIs.
Why does copy image fail in some browsers?
Copying a bitmap uses the async Clipboard API with image/png blobs. Some browsers require a secure context (HTTPS or localhost), user permission, or disallow image clipboard writes entirely. If copy fails, use download instead and attach the file manually.