Honest first: the physical limit
Brightening means amplifying existing image information — not inventing missing information. Where the sensor captured light (the subject is faintly recognizable), a lot can be rescued. Where everything is pitch black, brightening produces only grey noise. Mnemonic: what you can make out, you can brighten; what's black is gone. With that expectation in mind, the rest almost always works.
The most important slider is "shadows," not "brightness"
The most common mistake: pulling "brightness" or "exposure." That lifts the whole image — including the bright areas, which then blow out (sky goes white, faces flat). The right lever for a too-dark photo is "shadows" (on some systems "blacks" or "lowlights"): it brightens the dark areas specifically and leaves the bright ones alone. The proven order:
- Raise shadows — brings the dark subject back.
- Nudge exposure up if the image still looks too dark overall.
- Correct contrast — brightening flattens the image; a little contrast gives it depth back.
- Lower highlights if bright spots are now too glaring.
Where these sliders live on every device
- iPhone: Photos app → "Edit" → slider icon → Exposure, Highlights, Shadows, Contrast.
- Android (Google Photos): open image → "Edit" → "Adjust" → Brightness, Shadows, Highlights, Contrast.
- Windows 11 (Photos app): open image → "Edit" → "Adjustments" → Exposure, Shadows, Highlights.
- Mac (Preview/Photos): "Tools" → "Adjust Color," or in Photos "Edit" → Light.
For more involved corrections in the browser — with no install — it's worth a look at Editing images in the browser, which compares the free web editors.
The noise problem
Brightening dark areas heavily brings up image noise — colored or grainy speckle. That's normal and the physical limit mentioned above: the shadows hold little signal, and amplifying the signal amplifies the noise too. Countermeasures:
- Don't overdo it — a slightly darker, clean image beats a brightened, noisy one.
- Use a subtle noise filter (in many apps under "Details" or "Noise reduction") — it smooths but softens the image.
- Convert to greyscale if color noise is especially distracting — a black-and-white image hides noise surprisingly well.
For next time: avoid dark photos
The best exposure correction is the one you don't need. When shooting in dark situations: tap the subject before you shoot (sets focus and exposure on it), drag the phone's exposure dial up a little, and hold the camera steady so the longer exposure doesn't blur.
In short
- Pull "shadows," not "brightness" — then nudge exposure.
- Every phone/OS has these sliders built in.
- Noise is the limit — don't overdo it.
- Pitch black is unrecoverable — capture the light next time.