How to fix an underexposed video with a brightness boost
- Step 1Drop the dark clip onto the tool — MP4, MOV, MKV, WEBM, AVI, M4V, and TS are accepted. The file stays in your browser — nothing uploads. Free tier handles files up to 1 GB, Pro up to 10 GB, Pro+Media / Developer up to 100 GB. There is no duration cap, only the size limit.
- Step 2Let the WebGPU preview load — The live preview shows your dark frame and updates instantly as you raise brightness and gamma. If WebGPU is unavailable, the preview is disabled — the sliders still apply on export, you just judge brightness from the exported file.
- Step 3Raise gamma first to lift the midtones — Gamma above 1 (try 1.4–2.0 for clearly dark footage) lifts the murky midtones where detail is buried, without flattening the blacks. This is the single most effective control for underexposure. Push it until faces and shadow detail emerge but before the image looks plasticky.
- Step 4Add a small brightness lift if still dim — If the whole frame is still too dark after gamma, nudge brightness up by a small amount (0.05–0.15). Brightness is a flat offset, so a little goes a long way — too much greys out the blacks and washes the image. Use it as a finishing touch, not the main fix.
- Step 5Tweak contrast to restore depth — Lifting shadows can flatten the image. A small contrast bump (1.05–1.15) puts the punch back. Watch the preview — stop when blacks feel solid again but you have not re-buried the detail you just recovered.
- Step 6Export the brightened MP4 — Export runs
eqover every frame and re-encodes with libx264 CRF 20, copying the audio. Full export requires Pro (the free tier gives one 720p preview/day). To clean shadow noise the brightening revealed, there is no denoiser in this tool — keep the lift modest, or compress with web-optimizer afterwards.
Which control for which exposure problem
For underexposure, gamma does the heavy lifting and brightness fine-tunes. The other two controls restore depth and colour after the lift.
| Problem | Primary control | Suggested value | Why |
|---|---|---|---|
| Murky midtones, blacks OK | Gamma | 1.4 – 2.0 | Lifts midtones on a curve, leaving blacks anchored — recovers buried detail |
| Whole frame uniformly dim | Brightness | 0.05 – 0.15 | Flat offset raises every pixel; small values avoid greying the blacks |
| Image flat after lifting | Contrast | 1.05 – 1.15 | Restores depth lost when shadows were raised |
| Colour looks weak after lift | Saturation | 1.05 – 1.20 | Raising exposure can desaturate; a small bump re-warms the image |
Brightness vs gamma for dark footage
The core distinction that makes the difference between a rescued clip and a washed-out one.
| Aspect | Brightness (-1..1) | Gamma (0.1..10) |
|---|---|---|
| Effect curve | Flat offset — every pixel +/− the same amount | Non-linear — lifts midtones most, blacks/whites least |
| Effect on blacks | Greys them out (raises the floor) | Leaves them roughly anchored |
| Best for | Small overall finishing lift | The main underexposure fix |
| Risk if overused | Washed-out, milky image | Plasticky midtones, amplified shadow noise |
Tier limits
Size caps and the daily preview allowance. Full brightened export requires Pro.
| Tier | Max file size | Export | Preview quota |
|---|---|---|---|
| Free | 1 GB | Preview only | 1/day at 720p |
| Pro | 10 GB | Yes | 5/day at 1080p |
| Pro+Media | 100 GB | Yes | Unlimited, up to 4K |
| Developer | 100 GB | Yes | Unlimited, up to 4K |
Cookbook
Brightness/gamma pairs for real underexposure scenarios. Start with the gamma value, then add brightness only if the frame is still dim, then restore depth with contrast.
Indoor clip shot with no lamp on
Classic dim-room footage. Gamma does most of the work; a small brightness lift finishes it, and a touch of contrast and saturation puts the life back.
Goal: rescue a dim indoor clip brightness = 0.08 contrast = 1.10 saturation = 1.10 gamma = 1.70 Result: faces and room detail emerge, blacks stay solid. Output: brightened.mp4 (H.264 CRF 20, audio copied)
Backlit subject (bright window behind a dark face)
The window is already clipped, so do not chase it — focus gamma on lifting the face. Brightness stays low so you do not blow the window further.
Goal: lift a backlit, silhouetted subject brightness = 0.04 contrast = 1.00 saturation = 1.05 gamma = 2.00 Note: the blown window cannot be recovered (clipped highlights). Gamma lifts the face; accept the bright background.
Footage one to two stops under
Mildly underexposed but otherwise fine. A moderate gamma lift plus a hair of brightness gets it to neutral without amplifying much noise.
Goal: correct a mild ~1.5 stop underexposure brightness = 0.05 contrast = 1.08 saturation = 1.10 gamma = 1.40 Result: clean, natural exposure; minimal noise lift.
Pushed too far (what over-lifting looks like)
A cautionary recipe. These values brighten aggressively but reveal sensor noise in the shadows and grey the blacks — included so you recognise the failure pattern in the preview.
Over-lifted (avoid): brightness = 0.35 contrast = 0.90 saturation = 1.00 gamma = 2.80 Symptoms in preview: milky blacks, visible grain in shadows. Fix: cut brightness back, lean on gamma, add contrast.
Brighten then compress for sharing
After rescuing exposure, the H.264 CRF 20 output is high-quality but large. Chain it into a compressor so the brightened clip is upload-ready.
Step 1 — color-grader: brightness=0.08 gamma=1.7 contrast=1.1 saturation=1.1 -> brightened.mp4 Step 2 — shrink for the web / messaging: /video-tools/web-optimizer (faststart web file) or /video-tools/discord-compressor (size-targeted)
Edge cases and what actually happens
Blown highlights cannot be recovered
By designBrightness and gamma can lift dark areas but cannot bring back highlights that were clipped to pure white in-camera (e.g. a bright window behind a backlit subject). There is no detail in a clipped pixel to recover. Lift the shadows and accept the bright area, or re-shoot with more headroom.
Brightening amplifies shadow noise
ExpectedUnderexposed footage hides sensor noise in the dark areas; lifting exposure makes that noise visible. The grader has no denoiser, so keep the lift modest and watch the WebGPU preview at full size. If noise is unavoidable, a slight resolution downscale via video-resizer can mask it.
Pure brightness boost looks washed out
ExpectedCranking brightness alone raises the black floor and produces a milky, low-contrast image. For underexposure, lead with gamma (which lifts midtones while anchoring blacks) and use brightness only as a small finishing touch, then restore depth with a small contrast bump.
WebGPU preview unavailable
Preview disabledWithout WebGPU, the live preview is off but the brightness/gamma sliders still apply on export. Grade conservatively and check the exported .mp4, since you cannot see the shadow-noise tradeoff live.
Output is always H.264 MP4
By designThe brightened clip exports as libx264 .mp4 at CRF 20 regardless of input container. If you need a different codec for delivery, pass the result to h265-encoder or video-transcoder.
File exceeds the tier size cap
RejectedFiles above your tier limit (Free 1 GB, Pro 10 GB, Pro+Media / Developer 100 GB) are rejected before processing. Trim with lossless-trimmer or upgrade.
Audio left untouched
PreservedBrightening only re-encodes the video track; audio is copied with -c:a copy, so the soundtrack is bit-identical. A silent source stays silent.
The fix is baked in
ExpectedThe brighter exposure is encoded into the output pixels — there is no editable exposure layer. Keep the original dark file in case you want to re-grade with different values later.
Free daily preview limit reached
Quota reachedFree tier allows one 720p grade per day; after that you see an upgrade prompt. Pro gives 5/day at 1080p; Pro+Media / Developer are unlimited at up to 4K.
Very dark frame previews almost black
ExpectedIf the source is severely under, the preview may look near-black until you raise gamma — that is correct. Push gamma up and the detail appears; if nothing appears, the data may simply not have been captured.
Frequently asked questions
What is the fastest way to fix a dark video here?
Raise gamma above 1 first (1.4–2.0 for clearly dark footage). Gamma lifts the midtones where detail is hiding without graying the blacks. Add a small brightness lift only if the whole frame is still dim, then a touch of contrast to restore depth.
Why not just turn brightness all the way up?
Brightness is a flat offset — it raises the black floor and produces a washed-out, milky image. Gamma is the right control for underexposure because it lifts midtones on a curve while leaving blacks anchored. Use brightness only as a small finishing touch.
Can it recover a blown-out window or sky?
No. Highlights clipped to pure white in-camera contain no recoverable detail — brightening and gamma only affect darker areas. Lift the shadows and accept the bright region, or re-shoot exposing for the highlights.
Will brightening make my video noisy?
It can — dark footage hides sensor noise, and lifting exposure reveals it. There is no denoiser in this tool, so keep the lift moderate and check the WebGPU preview at full size. A slight downscale afterward can help mask grain.
Is my dark clip uploaded to fix it?
No. The file is read and re-encoded in your browser via FFmpeg.wasm. A private or sensitive dark clip never leaves your machine.
What controls are available for exposure?
Brightness (-1 to 1) and gamma (0.1 to 10) handle exposure; contrast (0 to 2) and saturation (0 to 3) restore depth and colour afterward. These four sliders are the entire grade.
What format do I get back?
An .mp4 encoded with H.264 (libx264) at CRF 20. The container and codec are fixed; the audio stream is copied unchanged.
Does fixing the picture affect the audio?
No. Audio is stream-copied with -c:a copy, so the soundtrack is identical to the source. Only the video is re-encoded.
How large a file can I brighten?
Free tier up to 1 GB, Pro up to 10 GB, Pro+Media / Developer up to 100 GB. No duration limit applies.
Why does the preview say WebGPU is unavailable?
Your browser or GPU lacks WebGPU support. The live preview is disabled, but the sliders still apply on export — judge the brightness from the exported file. A current Chrome/Edge build usually restores the preview.
Can I fix a batch of dark clips with the same settings?
Yes. Add multiple files and the tool batches them, applying the same brightness/gamma/contrast/saturation to each and producing one MP4 per clip. Batch size depends on tier. See /video-tools/solutions/match-video-color-batch-grade-set.
Why does export require Pro?
Full-resolution graded export is a Pro feature. The free tier gives one 720p graded preview per day so you can test the tool first; Pro unlocks 5/day at 1080p and Pro+Media / Developer make it unlimited at up to 4K.
Privacy first
Every JAD Video tool runs entirely in your browser via WebCodecs and FFmpeg (WebAssembly). Your video files never leave your device — verified by zero outbound network requests during processing.