ON-SCREEN TEXT BLOG / 8 MIN READ

How do I check the text contrast in my video?

If your titles and captions vanish the second the shot behind them gets bright, the contrast is too low. Here is how to check it in seconds, the targets worth aiming for, and how to keep text readable across the whole clip.

4.5:1minimum contrast ratio
~85%watch muted, text matters
1sto read it or lose it
0–100craft score

By Thomas, founder of CutScore · Updated June 2026

TEXT CONTRAST CHECK · titles_v3.mp4
A colour-grading panel open on an editing monitor, the desk where on-screen titles and captions get a final contrast check before the video is published.
CRAFT SCORE
FIXES ADVISED
checking text against the shot
Title low contrast on bright pan · add backing00:34
Caption contrast OK · ≈ 6:1
Thin font over skin tone · add stroke01:52
The 30-second answer To check the text contrast in your video, run three quick tests. First, the squint test: half-close your eyes at the screen, and if a title or caption smears into the background, it fails. Second, the worst-screen test: watch it on a phone at arm's length, brightness low, and read each line in under a second. Third, scrub the moments where the shot behind the text gets bright (a window, a sky, a white wall), because that is where plain white or black text disappears. Aim for a contrast ratio of about 4.5 to 1 between text and background, and if that feels fiddly, that is exactly the moment CutScore checks for you.
WHY TEXT VANISHES

I have shipped a video where the lower-third title was, in my words at the time, "totally fine." It was fine on my graded, calibrated monitor, at full brightness, in a dark room. On a phone, outdoors, the white text sat on a white kitchen counter for four seconds and simply was not there. Nobody read my name. The title might as well have been invisible ink.

Here is the trap. Contrast is not a property of the text. It is the relationship between the text and whatever is directly behind it, and in a video that background moves. You place a caption against a dark hoodie, it reads beautifully, and then the camera pans and the same caption is now sitting on a bright sky. Same colour, same font, completely unreadable. Static design tools let you eyeball contrast once. Footage makes you check it across every shot the text appears in.

And it matters more than you would guess, because a large share of people watch with the sound off. The text is doing the talking. If it is hard to read, the message does not land, no matter how good the writing was. So checking contrast is not pedantry. It is checking whether the words on screen actually reach anyone.

THE CHECKS

Four ways to check text contrast in your video.

None of these need a colour scientist or a plugin. They take seconds each, and between them they catch almost every readability problem before it goes live.

CheckHow to do itIt fails if
The squint testhalf-close your eyesThe text smears or blends into the background instead of staying a clear shape.
The worst-screen testphone, low brightnessYou hesitate, or have to stop and stare, to read a line at arm's length.
The bright-shot scrubjump to every panWhite or black text disappears the moment the background turns bright or busy.
The contrast-ratio glanceaim ≈ 4.5:1Text and background sit too close in tone for a quick, confident read.
The fastest one is the squintStep back, half-close your eyes, and play the clip. Your blurred vision is roughly what a small phone screen across a room gives someone. If the words survive that, they will survive most viewing conditions. If they melt into the shot, the contrast is too low and no font choice will save it.
SKIP THE FRAME-BY-FRAME

Checking text against a moving background, shot by shot, gets old fast. CutScore scans every title and caption against the footage behind it and flags the exact moments contrast drops too low.

Join the waitlist
THE TARGETS AND THE FIXES

What "enough contrast" actually means.

The number worth knowing: 4.5 to 1

Web accessibility guidelines (WCAG) put a useful stake in the ground: a contrast ratio of at least 4.5 to 1 between text and its background for normal text, and around 7 to 1 for small or thin type. You will almost never measure this exactly on moving footage, and that is fine. The point is the intent. White on light grey might be 1.5 to 1, which fails badly. White on a dark plate might be 12 to 1, which is comfortable on any screen. Knowing the target tells you which side of the line you are gambling on.

The fix that always works: a backing plate

If you take one thing from this, take this. A solid or semi-opaque box behind your text makes the contrast constant, no matter what the shot does behind it. The background can pan from a cave to a snowfield and your text never flinches, because it is no longer sitting on the footage, it is sitting on your plate. Even a soft drop shadow or a dark gradient at the bottom of the frame does most of the job. This is why broadcast lower-thirds and good captions almost always have a backing, and why the readable ones rarely use bare white text floating on the picture.

An editing desk with a timeline and preview open, the place where on-screen titles get a backing plate and a contrast pass before export.
A backing plate makes contrast constant, whatever the shot does behind the text. Photo: Jakub Żerdzicki / Pexels.

When you cannot use a plate: stroke and shadow

Sometimes a box looks heavy, or the style calls for clean text on the picture. Then your friends are a thin outline (a stroke) and a subtle drop shadow. A one or two pixel dark stroke around white text gives every letter its own little edge of contrast, so it survives a bright background. A soft shadow does the same trick from below. Use them together and even thin, elegant fonts stay legible. Just keep the stroke tasteful: a thick black outline turns your title into a ransom note.

Contrast is not the whole readability story

Contrast is the big one, but it works alongside two siblings. Size: if the font is tiny, even perfect contrast loses, which is why caption font size matters as much as colour. And placement: text that drifts under the platform's interface or off the edge of the frame fails for a different reason, which is the whole problem of where you put text so it is not cut off. Check all three together and your captions are genuinely readable, not just technically present.

RATHER SEE IT THAN READ IT?

Here is a real CutScore coaching report for an everyday video: on-screen text scored against the footage, with the low-contrast moments timestamped and the fix spelled out.

See a sample report
SHORT ON TIME

If you only fix three things.

Most contrast failures come down to these three. Fix them and your text reads on the worst screen your audience owns.

1
2-MIN FIXTEXT
Add a backing plate to every title and caption
A semi-opaque box behind the text makes contrast constant, whatever the shot does. It is the single fix that survives a bright pan, a busy background, and a viewer on full brightness in sunlight. Around 70% opacity black is a safe default.
How Drop a rounded rectangle behind the text layer, set it to roughly 60 to 75% black, and nudge the padding so the box hugs the words.
2
QUICKTEXT
Run the squint test on every text moment
Half-close your eyes and play the clip. If a line smears into the picture, the contrast is too low right there. This catches the one bright shot in an otherwise dark video, which is exactly the frame plain white text betrays you on.
How Scrub to each title and caption, blur your eyes, and ask: is this still a clear shape, or has it dissolved?
3
EDITTEXT
Stop trusting your edit monitor
Your calibrated screen at full brightness flatters contrast that falls apart on a phone outdoors. Check on the worst screen you own, at low brightness, before you decide the text is fine. That is the device most of your audience is actually using.
How AirDrop or upload a draft, watch it on your phone at arm's length, brightness down, and read every line cold.
THREE WAYS TO RUN THE CHECK

By eye, by ratio, or in one pass.

OPTION 01

By eye, on the worst screen

Free and surprisingly good. Squint test, then a phone at arm's length on low brightness. The catch is consistency: you have to remember to do it on every text moment, and your eyes adapt fast. Best done cold, after a short break, on someone else's device if you can.

OPTION 02

By measuring the ratio

Accurate but slow on video. You can sample the text colour and the background colour in any frame and run them through a contrast-ratio checker, aiming for 4.5 to 1 or better. Honest work, but the background changes every shot, so you are checking dozens of frames by hand. Most people will not.

OPTION 03

With a coach in one pass

Hand the file (or a link) to CutScore. It scans your on-screen text against the footage behind it, flags the moments contrast drops below readable, and tells you which shots need a plate, a stroke, or a bigger font, with timestamps. See a sample report.

How CutScore checks your text for you CutScore is an AI video quality coach for pre-publish QC, and on-screen text is one of the families it measures. It reads where your titles and captions sit, compares them against the footage directly behind them, and flags the frames where contrast, size or placement drop below readable, so a bright pan or a busy shot can not quietly eat your words. You get one 0 to 100 score, the timestamped evidence, and a prioritised list of fixes, before anyone else watches. It judges the craft of the video itself, not your tags or thumbnails. More on the method and the standards.
QUESTIONS

Frequently asked.

Do the squint test first: half-close your eyes at the screen, and if the text smears into the background it fails. Then watch it on a phone at arm's length, at low brightness, with a bright shot behind the text. If you can still read every word in under a second, the contrast is fine. If you hesitate, add a backing plate or a stroke.
Aim for the spirit of the WCAG accessibility rule: a contrast ratio of at least 4.5 to 1 between the text and whatever is directly behind it, and closer to 7 to 1 for small or thin fonts. You rarely measure this exactly on moving footage, so the safer move is a solid or semi-opaque backing box, which makes the ratio constant no matter what the shot does behind it.
Because the shot behind it changes. White text sits perfectly on a dark interior, then the camera pans to a bright window or a white shirt and the same text vanishes. Plain white or plain black text is gambling on the background staying one tone. A backing plate or a contrasting outline removes the gamble, so the text stays readable across the whole clip.
Yes. CutScore is an AI video quality coach. It scans your on-screen text and captions against the background behind them, flags the moments where contrast drops below readable, and tells you which shots need a backing plate or a bigger font, with timestamps, before you publish.
EARLY ACCESS

Make sure every word is readable.

CutScore checks your on-screen text against the footage behind it and tells you exactly which shots need a fix, with the evidence to back it up. Join the waitlist for early access.

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