iPhotoEditor

Every tool runs in your browser. Your photos never leave your device — see how that works.

Upscale an Image 2× or 4×

Enlarge a photo to double or quadruple its dimensions without an account, a fee, or a queue behind someone else's GPU - the scaling math runs on the device in front of you. Two honest modes: a fast resampler that works everywhere, and a small neural model where your hardware can carry it.

Loading the tool…

How it works

  1. Load the image and choose 2x or 4x.
  2. Pick a mode: Fast (stepped resampling, works on any device) or ML (Real-CUGAN, offered when a memory check passes).
  3. Wait for processing - the ML mode takes longer but synthesizes texture the fast mode cannot.
  4. Compare against the original at 100 percent, then download.

Worth knowing

The fast tier enlarges in repeated 2x steps with adaptive sharpening applied at each stage - a pipeline that produces clean, natural enlargements with none of the stair-stepping of naive scaling. What it deliberately does not do is invent detail. Resampling can only redistribute the pixels you gave it, so this page will never claim the fast mode "enhances" anything: it is the right choice when you need bigger dimensions with no surprises, on any hardware, in about a second.

The ML tier runs Real-CUGAN, an MIT-licensed super-resolution network that is remarkably compact at 2.6 MB - smaller than many of the photos it enlarges. Instead of interpolating between existing pixels, it predicts plausible fine texture learned from training data, which is why fabric weave, foliage and hair come out convincingly detailed rather than merely smooth. The word to hold onto is plausible: the network makes an educated guess at what detail belonged there, not a recovery of what the camera saw.

Neural upscaling is memory-hungry in ways phones punish, so the ML mode is gated behind a quick benchmark of available memory on mobile devices. If your device fails the check, the option is disabled with an explanation instead of letting the tab crash halfway through a 4x pass - an honest trade most upscaler pages avoid by silently doing the work on a server instead.

When is upscaling actually worth it? Printing at a larger size, recovering a heavily cropped composition, and meeting a platform's minimum-dimension rule are the genuine cases. What no upscaler can legitimately do is CSI-style recovery: text and faces that are unreadable at the original size do not become trustworthy at 4x, because any legibility the ML mode adds is synthesized, not restored.

The neural upscaler here, Real-CUGAN, is a 2.6 MB download - roughly one-seventeenth the size of the background removal model - yet it synthesizes texture that pure resampling mathematically cannot produce.

Verify it yourself: open your browser's DevTools, switch to the Network tab, and use this tool — you will see no upload request. Or load the page, go offline, and it still works.

What this tool will not do

  • The fast mode will not invent detail - a license plate unreadable at 1x is still unreadable at 4x.
  • The ML mode is withheld on devices that fail the memory benchmark, and the tool says so rather than crashing mid-process.
  • It will not fix blur or noise before enlarging - upscaling magnifies existing flaws along with everything else.

Upscaling modes

ModeMethodModel sizeBest for
FastStepped 2x resampling + adaptive sharpeningNoneAny device; clean enlargement with no invented detail
MLReal-CUGAN super-resolution (MIT license)2.6 MBTexture-rich photos on capable hardware

Questions people ask

How can I increase image resolution for free without a watermark?

Load the image here, pick 2x or 4x and a mode, and download. There is no watermark, no output cap and no account, because your device does the computation.

Does upscaling add real detail?

The fast mode does not - it resamples what exists. The ML mode synthesizes plausible detail learned from training data, which looks convincing but is a prediction, not a recovery.

Why is the ML option disabled on my phone?

A memory benchmark runs before offering the neural mode, and your device did not pass it. This prevents the tab from crashing partway through; the fast mode still works.

Should I pick 2x or 4x?

Use the smallest factor that meets your target size. 4x quadruples each dimension - sixteen times the pixels - and magnifies any flaw in the original accordingly.

Will an upscaled photo print well?

Often yes - printing is the strongest use case, since ink spread is forgiving. Upscale, inspect at 100 percent, apply light sharpening, and print a test section if the job matters.

Can it make blurry text readable?

No, and be wary of anything the ML mode appears to "reveal" in unreadable text - synthesized strokes are guesses and should never be treated as evidence.

Usually the next step

More in Edit & Enhance

This page processed nothing on any server — there is no server. The technical explanation.