Redimensionar imagens online
Altere as dimensões das suas imagens para qualquer tamanho. Gratuito, privado e instantâneo — tudo roda no seu navegador.
100% Privado — Seus arquivos nunca saem do seu dispositivo. Todo o processamento acontece no seu navegador.
Solte sua imagem aqui
ou clique para selecionar — JPG, PNG, WebP suportados
Tamanho original
Predefinições rápidas
Resultado
Como funciona o redimensionador de imagens?
Esta ferramenta usa a API Canvas integrada ao seu navegador para redesenhar sua imagem nas novas dimensões que você especificar. Todo o processo é executado localmente no seu dispositivo — suas imagens nunca são enviadas para nenhum servidor.
Tips for Better Image Resizing
- Lock the aspect ratio — Keep the aspect ratio locked (the default) to prevent your image from looking stretched or squished. This ensures width and height scale proportionally whenever you change either dimension.
- Use percentage presets for quick scaling — The 25%, 50%, and 75% presets are the fastest way to create thumbnails or reduce file size. A 50% reduction cuts the pixel count by 75%, dramatically shrinking the file while keeping proportions perfect.
- Pick dimension presets for specific targets — Use built-in presets like 1920×1080 (Full HD), 1280×720 (HD), or 800×600 for common web and social media sizes.
- Downscale rather than upscale — Shrinking an image preserves quality because the browser discards pixels. Enlarging forces the browser to interpolate new pixel data, which causes blurriness.
- Choose the right output format — After resizing, export as WebP for the smallest file size, JPEG for photographs, or PNG when you need transparency.
- Resize before compressing — If you plan to both resize and compress, resize first. Reducing dimensions first means the compressor has fewer pixels to process.
- Check the final dimensions display — Always verify the output dimensions shown below the width and height inputs before downloading.
When to Resize Your Images
- Social media profile pictures and banners — Each platform has specific dimension requirements (e.g., 1080×1080 for Instagram posts, 1500×500 for Twitter/X headers). Resizing ensures your images display perfectly without awkward cropping by the platform.
- Website and blog optimization — A 4000×3000 camera photo is far too large for a blog post. Resizing to 1200px wide before uploading cuts load time dramatically.
- Email-friendly images — Attaching full-resolution photos to emails wastes bandwidth and may exceed size limits. Resizing to 1280×960 or smaller makes images load instantly in email clients.
- Thumbnail generation — Use the 25% preset to quickly create thumbnail versions of product photos, gallery images, or portfolio pieces.
- Print preparation — When preparing images for print, resize to match your print size at 300 DPI — for example, a 4×6 inch print needs a 1200×1800 pixel image.
- E-commerce product listings — Marketplaces like Amazon, Etsy, and eBay have minimum and maximum image size requirements.
Perguntas frequentes
Redimensionar reduz a qualidade?
Ampliar uma imagem além do seu tamanho original pode causar algum desfoque, pois o navegador precisa interpolar novos pixels. Reduzir dimensões preserva bem a qualidade. Para melhores resultados, apenas reduza ou mantenha próximo ao tamanho original.
O que é o bloqueio de proporção?
Quando a proporção está bloqueada (padrão), alterar a largura ajusta automaticamente a altura para manter as mesmas proporções — e vice-versa. Isso evita que sua imagem fique esticada ou achatada. Você pode desbloquear se precisar de proporções personalizadas.
O que são as predefinições rápidas?
As predefinições permitem redimensionar rapidamente para dimensões comuns. As predefinições de porcentagem (25%, 50%, 75%) escalam em relação ao tamanho original. As predefinições de dimensões (1920×1080, 1280×720, etc.) definem valores exatos em pixels — útil para redes sociais, miniaturas ou publicação web.
What are the best image sizes for social media?
Common social media sizes include 1080×1080 for Instagram posts, 1200×630 for Facebook shared images, 1500×500 for Twitter/X headers, and 1280×720 for YouTube thumbnails. Use the dimension presets in ImgLab to quickly hit these targets, or type custom dimensions with aspect ratio lock enabled.
Can I make a small image larger without losing quality?
Upscaling a raster image always involves some quality loss because the browser must generate new pixels that did not exist in the original. Small increases (up to 150%) are usually acceptable, but doubling or tripling an image's size will produce noticeable blurriness. For the best upscale results, start with the highest-resolution source image you have.
Can I resize multiple images at once?
The resize tool currently processes one image at a time, allowing you to fine-tune dimensions for each photo. For batch resizing, you can quickly process images one after another — just drop a new image after downloading the previous one. Each image retains your last-used dimensions and settings for faster workflow.
Does resizing change the DPI/PPI of my image?
ImgLab resizes by pixel dimensions, not by DPI. DPI (dots per inch) only matters for print — it defines how many pixels fit in a physical inch. A 3000×2000 image printed at 300 DPI produces a 10×6.67 inch print. The tool changes the pixel count; your print software controls DPI when you output to paper.