Convertisseur d'images en ligne

What Convertisseur d'images does

Converting an image changes its file format while keeping the picture. You need it when a website, app or printer does not accept a format, for example an iPhone HEIC photo, a WEBP image saved from a browser, or a PNG that should become a smaller AVIF.

The tool decodes the file into plain pixels with your browser's image decoder, then encodes those pixels again in the new format. HEIC photos the browser cannot open use a built-in HEIC decoder. Only the pixels are carried over: the width and height stay the same (except for ICO, which is scaled to the icon size), and metadata is not copied.

Comment utiliser Convertisseur d'images

1. Déposez vos fichiers PNG, JPG, WEBP, AVIF, HEIC, JFIF, GIF, BMP, SVG et ICO dans la zone, ou cliquez pour les choisir.
2. Choisissez le format de sortie (PNG, JPG, WEBP, AVIF, BMP et ICO) et les options souhaitées.
3. Cliquez sur Convertir. La conversion se fait sur votre appareil.
4. Téléchargez chaque fichier, ou tous à la fois dans un ZIP.

When to use Convertisseur d'images

• Turn iPhone HEIC photos into JPG so they open in Windows apps, online forms and older photo viewers.
• Save WEBP images downloaded from a website as PNG or JPG so they can be edited in any program.
• Convert large PNG screenshots or product photos to WEBP or AVIF so web pages load faster.
• Make a website icon by converting a square logo into an ICO file between 16 and 256 pixels.

Settings explained

Output format

Chooses the format to save. JPG suits photos, PNG keeps sharp edges and transparency, WEBP and AVIF give smaller files, BMP is uncompressed and ICO is for icons. Shown only when the tool offers several formats.

Quality

Shown for JPG, WEBP and AVIF output. It ranges from 10 to 100 and starts at 90. Values between 75 and 90 give small files that look the same as the original on screen.

Background color

JPG and BMP cannot store transparency, so transparent pixels are filled with this color. The default is white. Pick a color that matches the page or document where the image will be placed.

Icon size

Shown when saving as ICO. The image is scaled to fit inside a square of 16 to 256 pixels and centered, with transparent space around it if it is not square. Use 32 or 48 for website icons.

SVG render width

Shown when SVG files are accepted. Sets the width in pixels used to draw a vector file before it is converted; the height follows the aspect ratio. Leave 0 to use the size defined in the file.

Format comparison

Qu'est-ce que le format PNG ?

PNG (Portable Network Graphics) est un format d'image créé par W3C en 1996. Il utilise une compression sans perte et gère la transparence. Les fichiers portent l'extension .png.

PNG was created in the mid-1990s as a free replacement for GIF, whose compression method was covered by patents at the time. It applies a filtering step and then compresses pixels with the DEFLATE algorithm, so every pixel is kept exactly. It supports full color, grayscale, palette images and a full alpha channel for smooth transparency.

PNG is the right choice for screenshots, logos, icons, diagrams, user interface graphics and any image with sharp edges, text or flat colors. It is also a safe format for images that need transparent backgrounds or will be edited again.

Because PNG is lossless, photos saved as PNG are often several times larger than the same photo saved as JPG or WebP. PNG has no lossy mode, and a standard PNG file cannot store animation.

PNG opens in every modern web browser, on Windows, macOS, Linux, Android and iOS, and in practically all image viewers, image editors, office suites and design tools. It is one of the most widely supported image formats.

Qu'est-ce que le format JPG ?

JPG (Joint Photographic Experts Group) est un format d'image créé par JPEG en 1992. Il utilise une compression avec perte et ne gère pas la transparence. Les fichiers portent l'extension .jpg ou .jpeg.

JPG, also written JPEG, is named after the Joint Photographic Experts Group, which wrote the standard. It splits an image into small blocks, transforms each block with a discrete cosine transform and discards the fine detail that the eye notices least. A quality setting controls how much detail is removed and therefore the file size.

JPG is the standard choice for photographs and other images with smooth color gradients, such as camera pictures, product photos and images for email or social media. It gives small files with good visual quality at moderate settings.

JPG does not support transparency or animation. Each time a JPG is edited and saved again, it loses a little more quality. Text, line art and sharp edges can show visible blocks or halos at low quality settings.

JPG is supported everywhere: in all web browsers, on all desktop and mobile operating systems, and on cameras, phones and printers. All image editors and office programs open it. It is the most compatible format for sharing photos.

Qu'est-ce que le format WEBP ?

WEBP (WebP) est un format d'image créé par Google en 2010. Il prend en charge la compression avec et sans perte, gère la transparence et peut contenir des animations. Les fichiers portent l'extension .webp.

WebP was developed by Google to make images on the web smaller. Its lossy mode is based on the VP8 video codec, and it also has a separate lossless mode. Both modes can include an alpha channel for transparency. The format also supports animation, so it can replace JPG, PNG and GIF in many cases.

WebP is a good choice for images on websites and in apps, where smaller files load faster. It works for photos, graphics with transparency and short animations, often at a smaller size than JPG, PNG or GIF.

Some older software, image editors, print services and upload forms still do not accept WebP. Lossy WebP always reduces color resolution, which can blur fine colored detail. At very high quality settings, the size benefit over JPG can be small.

All current major browsers display WebP, including Chrome, Edge, Firefox and Safari on recent versions of macOS and iOS. Windows, macOS, Android and most modern image editors open it, but some older desktop programs do not.

Qu'est-ce que le format AVIF ?

AVIF (AV1 Image File Format) est un format d'image créé par Alliance for Open Media en 2019. Il prend en charge la compression avec et sans perte, gère la transparence et peut contenir des animations. Les fichiers portent l'extension .avif.

AVIF stores images compressed with the AV1 video codec inside a HEIF-based container. It was developed by the Alliance for Open Media, a group that includes major browser and technology companies, as a royalty-free format. It supports high bit depth, wide color, HDR, transparency and image sequences.

AVIF is best for web images where file size matters most. It often produces smaller files than JPG or WebP at similar visual quality, especially for photos, and it is useful for HDR and wide color images.

Encoding AVIF is slow compared with JPG or WebP, especially at high quality settings. Many image editors, older devices and upload forms do not accept it yet. Fine detail and texture can look smoothed at low quality settings.

Current versions of Chrome, Edge, Firefox and Safari display AVIF. Recent Windows, macOS, iOS and Android versions can open it, sometimes with an extra codec extension, but support in editors, office software and older systems is incomplete.

Pourquoi utiliser l'outil Convertisseur d'images de FansBond

La plupart des convertisseurs en ligne envoient vos fichiers sur leurs serveurs. L'outil Convertisseur d'images de FansBond fait tout le travail dans votre navigateur, grâce à WebAssembly et aux API modernes des navigateurs. Vos fichiers restent sur votre appareil, ce qui est plus sûr pour vos photos privées, vos contrats et vos projets non publiés, et c'est souvent plus rapide puisqu'il n'y a rien à envoyer ni à télécharger.

Pas de file d'attente, pas de filigrane, pas de compte. Une fois la page chargée, l'outil continue de fonctionner même avec une connexion lente.

Tips for the best result

• Animated GIF and WEBP files are converted from their first frame only. Use the GIF tools if you need to keep the animation.
• Use PNG for screenshots, logos and images with text. Lossy formats can blur sharp edges and add faint marks around letters.
• An ICO file made here contains one size. If you need several icon sizes, convert the same logo again with a different icon size.
• Converting a JPG to PNG does not bring back detail lost to JPG compression; it only prevents further loss when you edit and save again.

How Convertisseur d'images works in your browser

When you add an image, the browser decodes it into raw pixels on your device. HEIC photos are decoded with a browser build of libheif, and AVIF with the libavif decoder. The pixels are then processed on an HTML canvas and encoded again in the format you picked.

JPG, PNG and WebP are encoded with your browser's built-in encoders, and AVIF with libavif compiled to WebAssembly. The compressors add MozJPEG for smaller JPG files and OxiPNG for lossless PNG optimization. Because everything runs locally, the speed depends on your device rather than on a server queue.

Privacy and security

Most online converters upload your files to a server, process them there and keep a copy for some time. Convertisseur d'images works differently: the code is downloaded to your browser once, and your files are read and written only on your device.

You can check this yourself: after the page has loaded, turn off your internet connection and the tool still works. This makes it safe for contracts, IDs, medical records, private photos and unreleased work.