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Brightness adjuster

Brighten or darken a photo with a slider, in your browser.

10 / 10 free files today

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All Editing & resizing tools →
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Open Brightness adjuster and you get an answer straight away, with no account to create. Its place is under Editing & resizing; Contrast adjuster and Saturation adjuster answer the questions closest to this one.

How to use it

  1. Open the tool — no signup or install needed.
  2. Enter your input or adjust the available options.
  3. Get your result instantly, then copy or download it.

Frequently asked questions

What does Brightness adjuster do?

Brighten or darken a photo with a slider, in your browser.

When would I actually use this?

Preparing an image for somewhere specific: cropping to an aspect ratio, resizing under an upload limit, straightening a photo, or shrinking a file that is too heavy.

What is the most common mistake?

Enlarging a small image and expecting detail. Upscaling invents pixels from the ones already there; it can smooth an image but it cannot add information that was never captured.

How is Brightness adjuster different from Contrast adjuster?

They sit next to each other but answer different questions: Contrast adjuster is the one to open when you need it to raise or flatten the contrast of an image without installing anything. Pick whichever matches what you're starting from — both are free.

Is there a tool for the next step?

Saturation adjuster is the closest one after this: Make colours richer or wash them out, from full colour to grey.

Where do the figures come from?

Editing goes through the browser's canvas, and the output carries no watermark. Re-saving a JPEG re-compresses it, so work from the original rather than from an already-edited copy.

Further reading

All guides →
ExplainerWatermarking: What It Protects, and What It Does NotA visible mark lives in the pixels, so it survives every copy — and degrades the image for every honest viewer at the same time. Measured: what a corner mark costs, what a tiled mark costs, and how each compares to metadata credit, Content Credentials and invisible watermarking.GuideHiding a Face, a Plate or an IBAN in an Image — PermanentlyBlur and pixelation are reversible — not by undoing the maths, but by guessing forwards. Against this tool's own blur and pixelate modes, a recovery attack returned the hidden value at rank 1 of 10,000. Both modes have since been removed. Here is what is left, and why it cannot be attacked the same way.How-toHow to Compress an Image Without Losing QualitySmaller images load faster and rank better. Here's how to shrink an image the smart way — format, resolution and compression level — without visible loss.GuideFavicons: What Sizes You Actually Need in 2026Five files cover every consumer that exists: the tab, the bookmark, the pinned tile, the Android home screen and the iOS home screen. The twenty-file lists are a dead browser matrix — with measurements showing what a 16-pixel icon can and cannot hold.How-toSending a Document for Signature: the Workflow, Not the LawWhether a drawn signature is valid is settled elsewhere. What decides whether your document actually gets signed is the order you ask people in, what the audit trail records, and six failure modes that have nothing to do with the law.ExplainerDPI, PPI, and What Actually Controls Print SizeThe DPI figure inside an image file is a label. It changes no pixels. Printed size is pixels divided by PPI — and DPI, properly used, means something else entirely: the printer's dots.
Brightness adjuster — OneKitly