Comment utiliser cette calculatrice
JPG, PNG, or WebP: what converting actually decides
The converter re-encodes one image into another format, and the real question is usually which format to choose. WebP is the modern default for the web: it typically compresses photos and graphics to a fraction of their original size while looking the same on screen, and every current browser displays it. PNG is the lossless option — it preserves transparency and fine detail exactly, which makes it right for logos, UI screenshots, and images that will be edited again. JPG remains the most widely compatible format: email clients, document processors, and many marketplace upload forms still expect it. The converter shows the exact output size before you download, so the trade-off is visible rather than guessed at, and you can compare two settings side by side before committing to either. For photos the difference is usually dramatic: the same picture at the same visual quality can be a fraction of the size.
Two conversions surprise people. A PNG with transparency converted to JPG loses the transparency — JPG cannot represent it — and the converter fills those pixels with white and says so on the page. A JPG converted to PNG rarely gains anything: PNG is lossless, but the source JPG already discarded detail, so you typically end up with a larger file of the same image; convert JPG to PNG only when the source is already lossless. GIF input is accepted too, but the result is a single frame — animation does not survive. Everything runs on your device in a background worker, so the image is never uploaded, logged, or stored — the main reason to use this tool instead of a random web converter that asks for your file first. If you are unsure which format fits, the format dropdown and the size readout together let you test before you choose.
How to convert: loading a file and setting options
Drop an image anywhere on the drop zone, or click it to open the file picker. JPG, PNG, WebP, and GIF are accepted; any other type is rejected with a message, and files over 25 MB are refused before any processing starts. Once the file is loaded you see its name, size, and pixel dimensions. For a conversion, choose the target format from the dropdown — JPEG (.jpg), PNG (.png), or WebP (.webp) — and set the quality slider, which runs from 1 to 100 with a default of 75. Press Convert and the image is decoded and re-encoded in a background worker; the result appears with the original size, the new size, the percentage saved, and the output dimensions, which match the input — this tool changes format, not scale. Re-processing runs on a copy of the pixels, so you can convert again with different settings without touching the original file.
Quality is a dial, not a verdict: lower values give smaller files with more visible artifacts, higher values give larger files with cleaner detail. A common workflow is to start around 75 to 80 for web photos and raise the value only when close inspection shows artifacts. Remember that the output is re-encoded from the decoded pixels, so anything a previous compression threw away stays lost — converting never recovers quality, which is why a JPG converted to PNG still looks like the JPG, only bigger. If the output is not smaller than the original, the page says so honestly and suggests a lower quality or a different format. When you are satisfied, the Download button saves the file under a name like toolivaro-convert.jpg with the new extension, and you can start over any time with the Reset button.
Reading the results: size, saving, and what gets dropped
The result panel shows four numbers: original size, output size, percentage saved, and pixel dimensions. The saving bar visualizes the ratio — a thin colored fill means the output is much smaller than the original; if the output is larger, the bar fills the track and the caption explains that this format or quality does not shrink this image. The percentage saved is relative to the original file, so an image that goes from 1 MB to 300 KB shows a 70 percent saving. Because the tool re-encodes, the output is a fresh file with its own compression: a WebP and a JPG both set to 80 produce different sizes, and the numbers shown are the sizes you will actually send. The dimensions line confirms that conversion leaves the pixel size alone — if you also need the image smaller or bigger, that is the resizer’s job, not this tool’s.
Read the disclosures too. Re-encoding strips embedded metadata — EXIF camera settings, GPS coordinates, copyright and contact notes — and the page states that on every result; that is usually a privacy win, but keep the original file if you need the metadata. The limits are honest: animated GIFs become a single frame, transparency does not survive a PNG-to-JPG conversion, and input is capped at 25 MB to keep processing responsive. Nothing you load is uploaded, logged, or stored — the pixels stay on your device, and the preview is a local object URL that is released when you reset. If a conversion surprises you, re-check the format and quality choices first: most surprises are the formats doing exactly what the page says they do, and the readout lets you confirm the result before anyone else ever sees it.
Comment le résultat est-il calculé ?
Convertir un PNG de 1,4 Mo en WebP pour le web
Une capture d'écran PNG avec une certaine transparence pèse 1,4 Mo. La conversion en WebP à 80 % de qualité produit généralement un fichier de 250 à 400 Ko — une réduction de 70 à 80 % avec un rendu visuellement identique à l'écran. Convertir le même PNG en JPG fait perdre la transparence et reste plus lourd que le WebP, c'est pourquoi le WebP est la recommandation par défaut pour les images web.
Exemple d'entrée et de sortie | Entrée | Valeur |
| image | 1.4 MB PNG with transparency |
| format | webp |
| quality | 80 |
| Résultat | ≈ 250–400 Ko en WebP (−70 % à −80 %) |
A transparent product PNG to JPG for a marketplace listing
You have a product shot — a pair of sneakers on a transparent background, saved as a 2.1 MB PNG — and the marketplace listing form accepts JPG and PNG but warns that JPG files upload fastest and render best in its gallery. You choose JPEG at quality 80. The converter decodes the PNG, re-encodes it as JPG, fills the transparent pixels with white, and reports the result: typically around 400–900 KB, with the transparency loss called out on the page. The honest mental model is photocopying a transparency film onto white paper: the see-through parts come back as white, and no setting on the tool recovers the original background later. For a studio shot on a light background that result looks intentional; for a logo meant to sit on colored pages it would be a problem, which is exactly why the page flags it. Before you download, compare: the same PNG converted to WebP usually comes out smaller and keeps the transparency, so if the gallery also accepted WebP, that would be the better trade — the tool makes this comparison cheap, one format change and one Convert click, showing the exact size and the percentage saved each time. When the listing platform’s preview renders the sneakers cleanly, download the JPG and upload it. The file is a fresh re-encode, which also means it carries no EXIF or GPS data from the original, and the dimensions shown match the PNG’s, so the listing’s aspect ratio is unchanged. If the gallery ever starts accepting WebP, keep the source PNG on your device — converting the JPG back would only compound the loss, while the original transparency is still recoverable from the untouched PNG.
Exemple d'entrée et de sortie | Entrée | Valeur |
| image | 2.1 MB PNG with transparency |
| format | jpeg |
| quality | 80 |
| Résultat | ≈ 400–900 KB JPG with white background (transparency lost) |
Pulling a poster frame from an animated GIF
A designer sends you an animated GIF, 1.8 MB, for a promo spot — but the CMS hero image field needs a still, and the site already serves WebP. Convert the GIF to WebP at quality 75. The converter takes the GIF’s first frame and re-encodes it, dropping the animation, and reports the result as a single-frame WebP, typically 200–600 KB — far smaller than the GIF, which mostly carried the weight of hundreds of frames. The analogy is pulling a single frame off a film reel: you keep the poster image, but the motion is gone, and no setting on the tool brings it back — which is why the page states the single-frame behavior plainly. Compare the saved still with the GIF’s opening frame on screen: WebP at 75 usually looks identical for a still image, which is why the hero slot loads fast. If the CMS asks for JPG instead, the same conversion in one more click gives a JPG of the same frame; the choice is a size-versus-compatibility trade, and the result panel shows both numbers before you decide. Either way, the exact output size and dimensions are shown before you download, so you can confirm the hero slot’s weight budget without guessing. The 1.8 MB GIF also demonstrates why conversion is not resizing: the output keeps the frame’s pixel dimensions, and if the hero slot needs a smaller size, that is the resizer’s job. And because everything runs on your device, the original GIF stays untouched — which matters when the designer later asks for a different frame, since the source animation remains exactly as it was sent, ready to convert again.
Exemple d'entrée et de sortie | Entrée | Valeur |
| image | 1.8 MB animated GIF |
| format | webp |
| quality | 75 |
| Résultat | ≈ 200–600 KB WebP — first frame only (animation dropped) |
Questions fréquentes
Quel format dois-je choisir ?
Le WebP pour le web : le meilleur poids pour les photos et les graphiques, pris en charge par tous les navigateurs modernes. Le PNG lorsque vous avez besoin de transparence ou de détails sans perte. Le JPG lorsque la compatibilité prime — e-mails, anciens systèmes et la plupart des téléversements sur les places de marché.
Que devient la transparence lors d'une conversion PNG vers JPG ?
Le JPG ne sait pas représenter la transparence ; le convertisseur remplit donc les pixels transparents en blanc et le signale sur la page. Si vous devez conserver la transparence, convertissez plutôt en WebP ou en PNG.
Pourquoi mon JPG devient-il plus lourd en PNG ?
Le PNG est sans perte : convertir un JPEG compressé avec perte en PNG ne peut pas récupérer les détails — cela ne fait que produire un fichier plus lourd. Ne convertissez en PNG que lorsque la source est déjà sans perte (PNG, ou une image fraîchement rendue).
Does converting remove my photo’s metadata?
Yes — re-encoding builds a fresh file, and embedded metadata such as EXIF camera settings, GPS coordinates, and copyright notes is not carried over. The page discloses this on every result. For most people that is a privacy benefit: the converted file you send carries none of the location or device details. If you need the metadata preserved, keep the original file alongside the converted one. This behavior is deliberate, not a bug.
What if my image is larger than 25 MB?
The file is refused with a clear message before any processing starts — nothing is uploaded in any case. If the image is close to the limit, resize it first: the image resizer here can shrink the pixel dimensions, which usually brings the file well under the cap, and you can then convert the smaller version. Photos from modern phones rarely need their full dimensions for a web upload anyway.
What quality setting should I use?
Start at 75 to 80 for photos going to the web — most screens cannot show the difference from higher settings, and the file stays small. Drop to 60–70 for large backgrounds where artifacts are hard to notice. Go to 85–90 when the image will be inspected closely, such as a product close-up. The result panel shows the exact output size and the percentage saved, so you can test two settings and pick the smaller file that still looks right.