HomeImage UtilitiesImage Resizer

exact size. instant resize.

resize photos to exact dimensions with aspect ratio lock. presets for Instagram, Twitter, Facebook, HD, and 4K.

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PNG, JPG, WebP

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What this tool does

Resize images by exact pixel dimensions, by percentage, or to fit a target. Aspect ratio can be locked or freed. Output as JPG, PNG, or WebP. Runs entirely in your browser — no upload, no copy on a server.

Pixels are not what most people think

The single most common “why does my image look blurry” issue is a confusion between the image's actual pixel dimensions and its display size. They are related but not the same number.

Modern phones and laptops have retinascreens that pack more physical pixels into the same display area. An image displayed at “500 pixels wide” on a 2x retina screen is actually 1000 device pixels wide. If the source image is only 500 pixels wide, the browser has to scale it up — and the result looks soft.

Practical rule: for any image you intend to display at sizeX, the source should be at least 2X in pixel dimensions. For a hero image displayed at 800px CSS wide, the source should be at least 1600px wide.

Upscaling does not invent detail

Resizing a 500×500 image up to 2000×2000 produces a 2000×2000 file that contains exactly as much real detail as the original. The extra pixels are interpolated — calculated from neighboring pixels rather than measured. The result looks softer than a true 2000×2000 source would.

AI upscalers exist that can plausibly fill in detail by guessing what a higher-resolution image “would have” looked like, but those are a different category of tool — and they are also expensive to run client-side. This tool does not do AI upscaling. If your goal is “make my small image look good large,” an AI upscaler is what you want.

Common target sizes by use case

  • Profile photo / avatar — 400×400 pixels, usually displayed at 80-120px. Round-cropped.
  • Email signature — under 200px on the longer side. Email clients shrink anything larger and the file weight matters for opening speed.
  • Social media post (Instagram, Facebook, LinkedIn) — 1080×1080 for square posts, 1080×1350 for portrait, 1200×630 for OG cards.
  • Web hero image — 1920×1080 or 2560×1440 for retina-friendly full-width.
  • Email attachment — under 1200px on the longer side. Attachments over 25MB get bounced by many servers.
  • Print at 300 DPI— multiply intended inches by 300 for pixel dimensions. A 4×6 inch print at 300 DPI is 1200×1800 pixels.

Aspect ratio: lock it unless you have a reason

Resizing without preserving aspect ratio stretches the image. Faces become wide or tall, circles become ovals, text becomes obviously distorted. The lock-aspect-ratio option in the tool defaults on for that reason.

If you need an image at a specific aspect ratio that does not match the source — for example, a landscape source for a square thumbnail — the right operation is crop, not stretch. The image crop tool handles that case.

If the file size after resize is still huge

Resizing reduces dimensions but does not aggressively re-compress. For maximum file-size reduction at a given target size, run the resized output through the compress tool after, with WebP or JPEG output and an 80-90 quality setting.

What runs in the browser

Every part of this — decoding the source image, resizing, re-encoding to the target format, packaging as a download — runs locally using the canvas API and the browser's built-in codecs. There is no server in the loop. Your image, which might be a screenshot of internal work or a personal photo, stays on your machine.

What this tool does

Resize images by exact pixel dimensions, by percentage, or to fit a target. Aspect ratio can be locked or freed. Output as JPG, PNG, or WebP. Runs entirely in your browser — no upload, no copy on a server.

Pixels are not what most people think

The single most common “why does my image look blurry” issue is a confusion between the image's actual pixel dimensions and its display size. They are related but not the same number.

Modern phones and laptops have retinascreens that pack more physical pixels into the same display area. An image displayed at “500 pixels wide” on a 2x retina screen is actually 1000 device pixels wide. If the source image is only 500 pixels wide, the browser has to scale it up — and the result looks soft.

Practical rule: for any image you intend to display at sizeX, the source should be at least 2X in pixel dimensions. For a hero image displayed at 800px CSS wide, the source should be at least 1600px wide.

Upscaling does not invent detail

Resizing a 500×500 image up to 2000×2000 produces a 2000×2000 file that contains exactly as much real detail as the original. The extra pixels are interpolated — calculated from neighboring pixels rather than measured. The result looks softer than a true 2000×2000 source would.

AI upscalers exist that can plausibly fill in detail by guessing what a higher-resolution image “would have” looked like, but those are a different category of tool — and they are also expensive to run client-side. This tool does not do AI upscaling. If your goal is “make my small image look good large,” an AI upscaler is what you want.

Common target sizes by use case

  • Profile photo / avatar — 400×400 pixels, usually displayed at 80-120px. Round-cropped.
  • Email signature — under 200px on the longer side. Email clients shrink anything larger and the file weight matters for opening speed.
  • Social media post (Instagram, Facebook, LinkedIn) — 1080×1080 for square posts, 1080×1350 for portrait, 1200×630 for OG cards.
  • Web hero image — 1920×1080 or 2560×1440 for retina-friendly full-width.
  • Email attachment — under 1200px on the longer side. Attachments over 25MB get bounced by many servers.
  • Print at 300 DPI— multiply intended inches by 300 for pixel dimensions. A 4×6 inch print at 300 DPI is 1200×1800 pixels.

Aspect ratio: lock it unless you have a reason

Resizing without preserving aspect ratio stretches the image. Faces become wide or tall, circles become ovals, text becomes obviously distorted. The lock-aspect-ratio option in the tool defaults on for that reason.

If you need an image at a specific aspect ratio that does not match the source — for example, a landscape source for a square thumbnail — the right operation is crop, not stretch. The image crop tool handles that case.

If the file size after resize is still huge

Resizing reduces dimensions but does not aggressively re-compress. For maximum file-size reduction at a given target size, run the resized output through the compress tool after, with WebP or JPEG output and an 80-90 quality setting.

What runs in the browser

Every part of this — decoding the source image, resizing, re-encoding to the target format, packaging as a download — runs locally using the canvas API and the browser's built-in codecs. There is no server in the loop. Your image, which might be a screenshot of internal work or a personal photo, stays on your machine.

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