One job, done properly

DPI is the most misunderstood number in photography, largely because it is not really a property of your file. It is a note stored alongside the pixels saying how densely to print them. Change it without resampling and nothing happens to the picture at all. What decides whether a print looks sharp is the pixel count, and the arithmetic is simple: inches multiplied by 300. A 4 by 6 print wants 1200 by 1800 pixels. A 12 by 18 wants 3600 by 5400. A 24 by 36 poster wants 7200 by 10800, which is more than a 24 megapixel camera produces. That is why upscaling and printing go together so often. Photographers hit the ceiling constantly, usually after cropping, and a good enlargement is the difference between a print that survives being looked at closely and one that only works from across the room. Our sizes map onto this directly: 2K covers A4, 4K covers A3 and most framed work, 6K and 8K take you into posters and banners.

Online, the photograph is the product. Nobody can pick your fabric up, so the only information a buyer gets about quality is what your image shows them, and every major marketplace has worked this out. They set minimum dimensions, they favour listings you can zoom into, and they push blurry uploads down the page. Meanwhile most small sellers are shooting on a phone, cropping hard to lose a messy background, and ending up with something that was fine on the screen they shot it on and thin everywhere else. Upscaling to 4K closes that gap for about the price of a cup of tea. Weave, stitching, grain, printed labels and the small imperfections that make a real object look real all survive the enlargement, so a buyer who zooms in finds more reasons to buy, not a wall of soft pixels. The same file then covers the listing, the thumbnail, the ad and the catalogue, which is the part sellers underestimate: you are not buying a bigger image, you are buying one photograph that stops needing to be reshot.

This is the use that gets the warmest emails, and it deserves a straight explanation of what to expect. Start with the scan, because everything downstream depends on it. Scan the print; do not photograph it. Use the highest resolution your scanner offers even if the file feels absurdly large, and work from the original print, never a copy of a copy. From there, upscaling resolves what the film recorded: grain becomes grain again instead of a grey wash, fabric gets its weave back, and faces recover the texture that makes them read as people instead of illustrations. What it does not do is repair. Scratches, water stains, creases, tape marks and torn corners are damage to the physical object, and an upscaler is not a restorer. It will not colourise black and white either, which we consider a feature: a colourised photograph is a guess wearing your grandmother's face. If the original is very small or very soft, be careful with faces. Where there is little information to work from, any model fills the gap with something plausible, and plausible is not the same as accurate. Use the slider, and trust your own eyes about whether the person looking back is the person you remember.

Occasionally, holding the line on faithfulness means handing back something a shade less dramatic than a competitor would, and we are at peace with that, because a portrait that is no longer your subject has failed at the only thing it was asked to do. The other half of the answer is knowing where the limits are and saying so out loud. Motion blur cannot be undone. Text nobody could read cannot be recovered. A face a few pixels across cannot be reconstructed reliably. Every one of those is written plainly in our help centre, before you spend anything, because a customer who knows what to expect is a customer who is happy with what arrives. Losing a sale to honesty costs us less than winning one and refunding it.

Use them. Genuinely. If you need one image at modest size for a blog post, a free tool will very likely do the job, and you should hear that here before you feel sold to. Where they tend to fall down is everything around the edges: a watermark across the result, a cap somewhere around 2x, queues that stretch into the evening, no way to keep your files, quiet ownership terms, and results that snap your photograph to a shape it never had. Our own free plan exists for exactly this reason. Real credits every month, no card, and the same output a paying customer gets, so you can judge it on your own photograph before deciding whether any of this is worth money. If it is not, no harm done.

These get used interchangeably and it causes real confusion at the point of buying. An image upscaler increases resolution: more pixels, more detail, a bigger file. A photo enhancer changes how the picture looks, meaning brightness, contrast, colour, sharpening and noise, usually at the size it already is. A photo enlarger is generally the same idea as an upscaler, borrowed from the darkroom. Increase image resolution and make an image bigger without losing quality are the phrases people actually type, and both describe upscaling. Image resizing is the plain version that adds pixels by averaging their neighbours, which is why it goes soft. Upscela is an upscaler first, and the free editor covers the enhancing side. Working out which one you need is usually the whole difference between fixing your problem and buying the wrong subscription.

There is a full photo editor here and nobody pays for it, on any plan, including no plan at all. Crop with a locked ratio or to exact pixel dimensions, straighten a horizon, rotate and flip, then work on brightness, contrast, saturation, warmth, tint, highlights and shadows with a live histogram showing what you are doing to the picture. There is an Auto button when you want a sensible starting point, and a hold to compare button for checking you have not gone too far. Export as JPG, PNG or WEBP at whatever quality and size you like. It runs entirely inside your browser. Your photograph is never uploaded to us, and that is precisely why it can be free: it costs us nothing to run, because it runs on your machine and not on ours. It also means it works perfectly well on a picture you have no intention of upscaling, and you are welcome to use it that way and never spend anything. The reason it sits beside the upscaler is the order the two belong in. Crop first, and every pixel you pay to enlarge is a pixel you decided to keep. Straighten first, and the enlargement is working on a level picture. Get the colour roughly where you want it first, and you are judging the result on its own merits. When you are done there is one button that hands the edited image straight to the upscaler, with nothing to save and nothing to upload twice.