How to Convert PNG to JPG (Windows, Mac, iPhone and Android)

The short answer

On a Mac: select the PNG in Finder, right-click, choose Quick Actions then Convert Image, and pick JPEG as the format. It writes a JPG next to the original and works on several files at once. On Windows: open the PNG in Paint, then use File → Save as → JPEG picture.

On iPhone, iPad and Android there is no visible “convert format” button in the photo apps, which is exactly why this search is so common. The reliable built-in route on iOS is a Shortcuts automation with the Encode Image action; on Android the practical route is a converter that runs in the browser. The in-browser tool linked at the bottom of this page works on all four platforms, accepts several PNGs at a time, and never sends your files anywhere.

One warning worth reading before you convert anything: PNG and JPEG are not two encodings of the same idea. JPEG has no transparency channel, so a PNG with see-through areas will have those areas filled with a solid colour. There is no undoing that after the fact, so decide what the background should be before you convert, not after.

• Mac or MacBook: Finder → Quick Actions → Convert Image → JPEG.
• Windows: Paint → File → Save as → JPEG picture.
• iPhone or iPad: a Shortcuts “Encode Image” recipe, or the browser route.
• Android: the browser route, since the gallery has no format switch.
• Any device, nothing installed, nothing uploaded: the linked in-browser converter.

PNG and JPG are not the same kind of file

PNG stands for Portable Network Graphics and its defining property is that it is lossless. When a PNG is encoded, the pixel values themselves are not altered; the file just stores them efficiently using a prediction filter plus DEFLATE compression, the same family of algorithms used by ZIP archives. Decompressing gives you back exactly the numbers you put in, one for one, bit for bit. That is why a PNG is the right choice for anything where an exact value matters: UI screenshots with crisp text, line art, logos, diagrams, charts, and any image that will be edited or converted again later.

JPEG gets its lossy reputation from a completely different strategy. It converts the image from RGB into a colour space that separates brightness from colour detail, splits the picture into 8×8 blocks, applies a cosine transform to each block, and then throws away precision in the coefficients the human eye is least sensitive to. A quality setting controls how aggressively that rounding happens. Colour detail is usually also subsampled, meaning colour information is stored at roughly half the resolution of brightness information. Nothing about that process is reversible: the discarded data is gone from the file.

PNG stores colour as red, green and blue plus an optional fourth channel, alpha, which records how opaque each pixel is on a scale from fully transparent to fully opaque. JPEG has no fourth channel in its standard form. There is nowhere in a baseline JPEG file to put an alpha value, which is why every converter must make a decision for you: it composites the image onto a background colour and flattens everything into three channels. White is the near-universal default because a transparent PNG pasted onto a white page should look unchanged.

The size consequences follow from all of this, and they are counter-intuitive at first. For photographs JPEG is dramatically smaller, because a photo is full of high-frequency detail that PNG has to store exactly. For flat graphics — a screenshot of an app, a logo on a solid background, black lines on white — PNG is often the smaller file, because long runs of identical pixels compress beautifully and there is no noise for JPEG to misjudge. So converting a screenshot to JPEG can make the file bigger and the text softer at the same time. Convert with a purpose: shrink a photo, or satisfy something that demands JPEG.

What “without losing quality” really means

The phrase is a small misnomer, and understanding why saves you from chasing a setting that does not exist. Going from a lossless format to a lossy one always discards something. The honest goal is not “no loss”, it is loss you cannot see, which is entirely achievable, and loss that will not hurt you later if the file gets edited, printed, or re-encoded again.

Three practical rules cover most of it. First, start from the highest-quality source you have and convert only once — JPEG damage accumulates, because each re-encode rounds the already-rounded numbers again, and the artifacts sharpen with every generation. Second, set quality around 80 to 90 for images that will be looked at closely, and 70 to 80 for ordinary web use; the drop from 95 to 85 is almost invisible while the size difference is often substantial, because the top of the slider buys you very little. Third, inspect the result at 100% zoom before deleting the original, looking specifically at text edges, high-contrast transitions, and flat skies or gradients, which are the three places JPEG reveals itself.

If the image contains text you need to stay razor sharp, or if you are converting for archival purposes rather than for delivery, keep the PNG. There is no JPEG setting that preserves a hard black-on-white edge exactly. If your actual problem is that the file is too large rather than that the format is wrong, that is a different job with a different tool: shrinking a PNG with a quality control usually means converting to JPEG, but reducing a JPEG you already have is a compression task, and a browser image compressor with an explicit quality slider gives you a smaller file without a format change.

On Mac and MacBook

A MacBook is a Mac, so the same two routes apply to both, and macOS is the platform where this needs no extra software at all. PDF and image conversion are treated as first-class operating system features, and the fastest path is in the Finder context menu.

Whichever macOS route you pick, the conversion writes new files rather than editing in place, so the original PNG survives and your folder ends up holding both — expect duplicates and rename or move the JPGs when the job is done. If Quick Actions does not offer Convert Image, you are on an older release of macOS, and Preview or the Terminal covers exactly the same ground. Both built-in routes are local and free, and neither one asks you to sign in anywhere.

Quick Actions: the one-click route, batch included

Select one or more PNG files in Finder, right-click, hover over Quick Actions, and choose Convert Image. Pick JPEG as the format, choose whether to keep pixels at their original size, and confirm. macOS writes new JPG files alongside the originals in the same folder, leaving the PNGs untouched.

This is the answer for most people on this search. It handles many files at once, it is genuinely free with no watermark and no account, and nothing leaves the machine because the conversion runs locally. The controls are deliberately minimal: you get format and resize, not a quality slider, so if you need to tune the output quality precisely use Preview instead.

Preview: one file with a quality slider

Open the PNG in Preview, then use File → Export rather than Duplicate. In the export sheet, choose JPEG from the Format menu and drag the Quality slider, which trades output quality against file size. Moving it changes the previewed result, so you can see artifacts before committing, and Preview shows the expected file size as you go.

Preview is also where the transparency question bites. A JPEG has no alpha channel, so exporting a transparent PNG flattens the see-through areas onto a solid background, and through Preview that background tends to come out black rather than the white most people expect. If you need a specific matte, add a deliberate background layer to the image first, or convert with a tool that states which background it composites onto. Either way, decide before you export, because the transparency is gone once the file is written.

The Preview sidebar can hold many open documents at once, but File → Export applies to the frontmost image only. For real batches, use Quick Actions or the command-line route below.

Terminal: sips for scripted batches

macOS ships a command-line image tool called sips. In Terminal, cd to the folder holding the PNGs and run `sips -s format jpeg *.png --out converted/`. It creates a converted folder and drops a JPG for every PNG in it.

This is worth knowing when you have hundreds of files, when you want the same settings applied identically across a set, or when you are folding the step into a script. sips is installed as part of the system, so there is nothing to download.

On Windows

Windows has no right-click “convert to JPEG” action, which is the single biggest source of confusion on this platform. Paint is the built-in answer, and it is quick for a handful of files.

The shape of the decision on Windows is simple: one file and no preferences means Paint, while a batch, a quality setting, or a file you would rather not hand to a third-party app means the browser route. Nothing about Paint is broken here, it is just single-file work with no controls, which is a poor match for the folder-full-of-screenshots case that prompts this search in the first place.

Paint: the built-in route

Right-click the PNG in File Explorer, choose Open with, then Paint. Then use File → Save as → JPEG picture, pick a folder, and save. Paint composites the transparent areas of a PNG onto white when it writes a JPEG, which is usually the result you want, and the original PNG is left untouched because you are writing a new file.

Paint's two real limitations are that it handles one file per save and that it gives you no quality control, so you accept whatever default the encoder uses. If you need to tune quality or push through twenty files, that is the point at which the browser converter or an installable command-line tool earns its keep.

Photos app

The Windows Photos application can re-save an image in a different format: open the PNG, open the ellipsis menu, and look for the save-as or export command, where JPEG appears among the format choices. The exact wording has moved around across Photos versions, so if you cannot find a format list there, Paint is the dependable route.

Photos is also the right tool when the image needs rotating or cropping before conversion. Make those changes first and save once, rather than editing after the format has already been discarded.

Windows: batches without clicking twenty times

There is no native batch image converter in Windows, so for volume work you install something or move the job to the browser. A free desktop tool such as ImageMagick does it from PowerShell in one line: `magick mogrify -format jpg *.png` converts every PNG in the current folder, and a `-quality 85` flag controls the output. It is a genuinely capable tool, but it is a command-line install, so most people are better served by the in-browser converter, which takes multiple files by drag and drop with nothing to install.

Be cautious with the free converter apps in the Microsoft Store. Many are thin wrappers around an upload, an ad bundle, or a watermark, and the ones that run locally are frequently just a front end for the same libraries that are already free.

On iPhone and iPad

Neither Photos nor the Files app exposes a format switch, so screenshots — which iOS writes as PNG — stay PNG no matter how many times you share them. There are three honest ways around it.

The gap is real rather than something you are failing to find: Apple gives you format control at capture time and in Shortcuts, but not in the photo browser. iPad follows iPhone for everything above, with the extra convenience that the Files app on iPad supports drag and drop between panes, so you can build a folder of originals and a folder of converted output and move between them with the same Shortcuts recipe.

Shortcuts: the built-in converter

The Shortcuts app ships with iOS and iPadOS. Create a shortcut with these actions: Select Photos (or Choose Files, if the PNG is in the Files app), then Encode Image with the Format set to JPEG, then Save File or Share. Run it, pick your image, and you get a JPEG back.

The Encode Image action also exposes a quality percentage, so this route is more controllable than most desktop ones. Build the shortcut once and it becomes a two-tap operation; add it to the Share Sheet so it appears wherever an image is open. It runs entirely on the device.

Safari: the browser route

Open the converter in Safari, tap to choose your files from the Photos library or the Files app, convert, and save the JPGs back to Photos or Files. This works identically on iPhone and iPad, needs no app install, and is the fastest option when you do not want to build a shortcut. Because the encoding happens in the browser on the device, the image is not uploaded anywhere.

Stop producing files that need converting

If the underlying complaint is camera output rather than screenshots, Settings → Camera → Formats → Most Compatible makes new photos be captured as JPEG instead of HEIF, and it makes transfers to a Mac or PC hand over compatible files. It is a capture setting, not a converter, so existing images keep whatever format they were saved in.

Screenshots are a separate case: iOS always writes them as PNG and there is no system preference that changes it, so PNG screenshots are exactly the case the shortcut or the browser route is for.

On Android

Android's gallery apps, including Google Photos, offer editing and resizing but no format selection when saving. The share sheet hands on the original file, so a PNG stays a PNG whatever route you take through it.

That holds across the mainstream vendor skins as well, not just on stock Android: Samsung's and other manufacturers' galleries let you save a copy and adjust size, but the copy keeps the source format. So on a phone the question is not which built-in app hides a convert button, but whether you run the job in the browser tab or install something — and for anything other than daily bulk work, the browser wins.

Chrome: the practical route

Open the converter in Chrome, tap the file picker, choose your PNGs from the gallery or from internal storage, convert, and the JPEGs land in your Downloads folder where any app can find them. This is the same on phones and tablets, requires no install, and keeps the images on the device because the encoding runs in the browser tab.

The one real constraint on a phone is memory. Converting a dozen full-resolution PNGs in one batch on a mid-range device can fail or stall, so split large jobs into smaller groups rather than selecting everything at once.

Apps, and when one is worth it

If you convert formats daily, a dedicated file-management or image app can add a batch action to the long-press menu. Choose carefully: read what the permissions actually request, and be suspicious of an app that needs network access for a job that a browser tab does offline. For occasional conversion the browser route is faster than installing anything.

Free options compared

“Free” covers a wide range of behaviour, and the differences rarely appear in the headline price. They appear as a watermark, a daily file cap, an account requirement, a size ceiling, or an upload — and the upload is the one that matters most, because a PNG is very often a screenshot containing your name, your email address, a conversation, or a document.

A useful filter before you commit to a service: read what it says about retention, and ask whether it explains where the processing happens. If the page's own copy talks about deleting your files after an hour, that confirms an upload; if it says the tool runs in your browser, nothing leaves the machine. The two categories below differ mostly in how much control you get over the output, not in price, because every one of them costs nothing.

• Built-in operating system routes (macOS Quick Actions and Preview, Windows Paint, iOS Shortcuts): genuinely free, local, no watermark, no upload. Limited on Windows and iOS for batches.
• Command-line tools such as sips on macOS and ImageMagick anywhere: free, local, scriptable, and the best option for large batches; the cost is that they are not point-and-click.
• Online conversion services: free tiers exist, but your image is uploaded to their server, processed there, and retained for a stated window before deletion. Fine for a landscape photo; a poor fit for an ID scan, a receipt with your address on it, or a screenshot of a private conversation.
• Freemium desktop apps: convert locally but stamp a watermark, cap resolution, or nag after a few files unless you pay.
• In-browser tools: no upload at all, because the encoding runs on your own device in the open tab. This is the same privacy category as the built-in OS routes, with batch support and a quality slider the OS routes often lack.

Choosing quality settings that hold up

If the converter offers a quality percentage or a 1–12 scale, treat the very top of the range as a mistake rather than a safe default. The last few points cost a disproportionate amount of file size: a maximum-quality JPEG can be far larger than one written at 85 while looking identical to anyone who was not told which was which. A sensible starting point is 85 for images people will zoom into, 75 for images displayed at a fixed small size, and 60 for thumbnails where file weight matters more than fidelity.

Where quality really is spent is on hard edges and on gradients. Look at text against its background at 100% zoom: ringing, a faint halo of colour around the letters, is JPEG saying it needs a higher setting. Look at skies and soft shadows: banding in visible steps means the quantisation is breaking a smooth ramp, and that is the artifact that gets worse when the file is later displayed against a dark interface or printed.

The other decision is dimensions. If the image only ever appears at 800 pixels wide, convert at 800 pixels wide. Halving the pixel dimensions cuts the file roughly four times as effectively as any quality setting, and it costs nothing in perceived sharpness when the display size never exceeds it. Converting format and resizing in the same step avoids a second re-encode, which is where quality is actually lost.

Common problems and how to fix them

The JPG has a black or white box where the transparent part was. Correct: JPEG has no alpha channel, so the converter composited the image onto a matte. Either pick a tool that lets you choose the background colour, add a deliberate background layer before converting, or keep the file as PNG or go to WebP, which does keep transparency and is accepted by every modern browser.

Colours shifted after conversion, especially on a Mac. This is a colour-profile issue rather than a codec issue. Display P3 and Apple Display screenshots carry a wide-gamut profile, and many converters discard the profile or convert to sRGB without preserving the appearance, so saturated reds and greens dull slightly. Convert with a tool that states its colour handling, or flatten to sRGB deliberately before converting so the shift happens once and visibly.

The JPG is bigger than the PNG. Expected for flat graphics, screenshots and line art, where PNG's exact-pixel compression beats JPEG's lossy model. Do not force the conversion for size; if the goal is a smaller file, downscale the PNG instead, or accept that the format change was for compatibility and not for weight.

Text looks soft or gritty after conversion. The quality setting is too low for an image dominated by high-contrast edges. Raise it, or keep the text as PNG and convert only the photographic part of the composition.

The upload was rejected because it demands JPEG. Check whether it also restricts file size — this is the scenario where a converter plus a compressor is the right pairing, since you need both the correct container and the correct weight before the form accepts the file.

You converted, then converted the result again. Every JPEG decode-and-re-encode round adds artifacts. Go back to your original PNG, adjust the setting, and produce one final JPEG rather than stacking generations.

Frequently asked questions