Redimensionneur d'Images
Resize images to any dimension
100 % gratuit. Fonctionne entièrement dans votre navigateur : vos fichiers et données ne quittent jamais votre appareil et rien n'est envoyé à un serveur.
Glissez-déposez les fichiers ici
ou parcourir pour importer
Supports PNG, JPG, WebP up to 20MB
Traité dans votre navigateur - votre fichier ne quitte jamais cet appareil.
À propos de cet outil
Resizing changes how many pixels an image contains - its width and height - which is a different operation from compressing, and the two are often confused. Compression makes the file smaller while keeping the same dimensions; resizing makes the image itself physically smaller or larger. In practice resizing usually saves far more space, because file size scales with the total pixel count: halving both width and height leaves a quarter of the pixels. The other thing worth understanding is that resizing down is safe and resizing up is not. Shrinking discards pixels the image genuinely had, so the result stays sharp. Enlarging has to invent pixels that were never captured, which is why an upscaled photo looks soft no matter what tool produced it. Everything here runs in your browser using its own canvas, so images are never uploaded and there is no queue.
Optimiser une image pour votre site web
L'ordre compte : redimensionnez d'abord pour que la compression ait moins de pixels à traiter, et convertissez en dernier. Chaque étape ci-dessous ouvre l'outil correspondant.
- 1TéléverserDéposez votre JPG ou PNG directement dans l'outil.
- 2RedimensionnerAjustez-la à la taille où elle est réellement affichée.Vous êtes ici
- 3CompresserRéduisez le fichier sans perte de qualité visible.Ouvrir
- 4Convertir en WebPGénéralement 25-35 % plus petit qu'un JPG.Ouvrir
- 5TéléchargerEnregistrez-la et mettez-la sur votre site.
Préparer une photo de produit pour une boutique en ligne
Supprimez l'arrière-plan, recadrez au carré, puis faites tenir le fichier sous la limite de taille de la plateforme.
- 1Supprimer l'arrière-planIsolez le produit sur fond transparent.Ouvrir
- 2Recadrer au carréLa plupart des marketplaces attendent un cadre 1:1.Ouvrir
- 3RedimensionnerFaites correspondre exactement les dimensions de l'annonce.Vous êtes ici
- 4Respecter une limite de tailleCompressez vers une cible en Ko précise.Ouvrir
Transformer une photo iPhone ou AVIF en quelque chose que tout le monde peut ouvrir
Les formats d'appareil photo modernes sont efficaces mais de nombreuses applications ne peuvent pas les lire. Convertissez, puis ajustez la taille selon la destination.
- 1HEIC vers JPGPour les photos venant directement d'un iPhone.Ouvrir
- 2AVIF vers JPGPour les images enregistrées depuis un site moderne.Ouvrir
- 3RedimensionnerAdaptez-la à sa destination.Vous êtes ici
- 4CompresserLe JPG est plus lourd que l'original - réduisez-le.Ouvrir
Comment utiliser cet outil
- Add your imageDrop it in or browse to select. The current pixel dimensions are shown so you know what you are starting from.
- Enter the new sizeSet a width and height in pixels, or scale by percentage. Presets cover the common social and display sizes.
- Decide about the aspect ratioLeave the lock on and the image scales proportionally. Turn it off only when you deliberately want to stretch to exact dimensions.
- Resize and downloadThe image is redrawn at the new size on your device and downloads immediately. Your original file is untouched.
Pourquoi l’utiliser
- Usually saves far more file size than compression alone, because you are removing pixels rather than re-encoding them.
- Aspect ratio lock prevents the stretched, squashed look that manual width and height entry causes.
- Runs on your device, so private photos never leave it.
- Presets for common target sizes, so you do not have to look up what a profile picture or thumbnail should be.
- No account, no watermark and no upload limit.
Usages courants
- Meeting an exact pixel requirement on a form, marketplace listing or job portal.
- Preparing images for a website, where full-resolution camera photos are wildly oversized.
- Making a profile picture or banner fit a platform's stated dimensions.
- Shrinking a batch of photos before emailing or messaging them.
- Reducing very large scans to a workable size before further editing.
Conseils pour de meilleurs résultats
- Keep the aspect ratio locked unless you have a specific reason not to. Stretching is immediately obvious on faces and text.
- Resize down from the original, not from an already-resized copy. Each resize loses a little sharpness.
- For web use, resize to roughly twice the display size to stay sharp on high-density screens, then compress.
- If you need a specific file size rather than specific dimensions, use Resize Image to KB instead.
- Resize first, then compress. Doing it in that order gives a much smaller file than compression alone.
Erreurs à éviter
- Enlarging a small image and expecting detail to appear. The pixels were never captured; upscaling only interpolates.
- Unlocking the aspect ratio by accident, which stretches the image without any warning.
- Resizing the original file and overwriting it. Keep the full-resolution version - you cannot recover it later.
- Confusing resizing with compression, then wondering why a "resized" image still exceeds an upload limit.
- Resizing images destined for print using screen dimensions. Print needs far more pixels than a screen does.
Formats pris en charge
- JPG
- PNG
- WebP
- GIF
Options disponibles
- Width
- Height
- Keep aspect ratio
- Output format
Questions fréquentes
Add your image above, enter the width and height you need or scale by percentage, and download. The resize happens in your browser, so nothing is uploaded.
Yes - no account, no limit on how many images you resize and no watermark on the output.
Not if the aspect ratio lock is on - the image scales proportionally. Turning it off and entering mismatched width and height will stretch the image to fit exactly those numbers.
No. Enlarging stretches existing pixels rather than adding real detail, so the result looks soft. For a better enlargement, the Image Upscaler uses multi-pass resampling designed for that purpose - though no tool can recover detail that was never captured.
Resizing changes the pixel dimensions; compressing changes how efficiently those pixels are stored. Resizing usually saves more space, and doing both - resize first, then compress - gives the smallest file.
Yes, substantially in most cases. File size roughly follows the total pixel count, so halving the width and height leaves about a quarter of the pixels and a much smaller file.
No. The resize uses your browser's canvas on your own device. The page keeps working with the network disconnected.
It varies by platform and changes regularly, which is why presets are provided. As a general rule, upload larger than the display size - platforms downscale well but cannot add detail to an undersized image.
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