Faint Line Detector
Can't tell if there's a second line? The faint line detector boosts the dye color in a photo of your test so a faint line stands out. It's free and runs in your browser. For an AI result, use the Pregnancy Test Scanner app.
Your photo is processed on your device. It is never uploaded.
How the faint line detector works
Test dye is colored because it soaks up some colors of light. Pink and red dye absorb green light, while blue dye absorbs red light. The detector looks at the one color channel where your test's dye is darkest, turns the photo into a grey picture of that channel, and then stretches the contrast. A pale pink stripe that blends into the white strip in the original becomes a clearly darker band.
Use Pink dye boost for pink or red lines and Blue dye boost for blue ones. Everything happens on your device, so you can try both views as often as you like.
Does a faint line mean you're pregnant?
It can: even a faint line can mean you're pregnant (Cleveland Clinic). How dark the line looks depends on how much hCG is in your urine, how sensitive the test is, and when you tested.
First-morning urine usually holds more hCG than urine later in the day (MedlinePlus), so a line that looks pale in the evening can look stronger on a morning test.
Faint line or a false alarm?
The detector makes any dark mark at the test position stand out, and not every mark is dye. Evaporation lines can appear if you wait too long to read a test (Cleveland Clinic), and they're usually described as grey or colorless. Indents are grooves in the test where the line would print. Shadows from your phone or fingers can fall across the window.
So after boosting, switch back to Original and check two things: whether the line has color, and whether you took the photo within the reading time. A line that looks grey, shows up only in a boosted view, or appeared late is unclear rather than a result, so test again in a few days.
What to do after a faint line
- Wait a few days and test again (NHS). Use first-morning urine if you can, because it usually has more hCG than urine later in the day (MedlinePlus).
- If a test is clearly positive, that result is almost certainly correct. Contact a doctor or midwife to start your pregnancy care (NHS).
- If your tests stay unclear or negative and your period still hasn't come, see a doctor (NHS).
Faint line detector questions
Is the faint line detector free to use?
Yes, it is free with no sign-up. It boosts the dye in your photo so a faint line is easier to see; for an AI result, scan the test with the Pregnancy Test Scanner app.
Will the detector say whether I am pregnant?
No. It only changes how your photo looks and never reads the test. A doctor or midwife can confirm a pregnancy.
Which setting should I use for my brand?
Pink dye boost suits tests with pink or red lines, such as First Response, Easy@Home, Wondfo and most cheap strips. Blue dye boost suits blue-line tests, such as some Clearblue tests.
Why does the boosted line look darker than the real one?
The detector stretches the contrast so small color differences look big. That makes a faint line easy to find, but it also means a boosted photo is not a fair measure of how strong the line really is.
Can line darkness tell me my hCG level or how many weeks pregnant I am?
No. Line darkness depends on the brand, how concentrated your urine is, the light and your camera, so it is not a hormone measurement.
Who can see the photos I check?
Only you. The detector works inside your browser and never uploads the picture anywhere.
Want an answer, not just a clearer photo?
The Pregnancy Test Scanner app reads your test with AI, Positive or Negative with a confidence score, and keeps every photo in a test diary.
Sources
- Cleveland Clinic. Pregnancy Tests
- MedlinePlus. Pregnancy Test
- NHS. Doing a pregnancy test