How the caption is printed
The picture is decoded in this tab at its own size. The caption is wrapped to the picture’s width at a size proportional to its height — never under 3% of it, because WhatsApp recompresses pictures and smaller type blurs — and drawn with the picture onto one canvas. The preview you see is that canvas, scaled to fit the screen, so the original-size download is the preview pixel for pixel.
Colours can be picked by hand or from the five main colours measured in the picture. Whichever you pick, the page works out the contrast between the caption text and what it sits on — for a see-through band, the band mixed with the picture under it — and says when it falls under the 4.5:1 level WCAG asks of ordinary text.
A caption, not a description
The caption under a news photograph and the alt text in its HTML do different jobs. The caption is read by everyone, beside the picture, so it adds what the picture cannot show: the name of the place, the date, why it matters. The alt text stands in for the picture for someone who cannot see it. Writing the same sentence into both makes a screen reader say it twice. This page keeps the two in separate fields and checks one against the other.
What it will not do
- It does not write the caption for you. Nothing on this site names what is in a photograph.
- It prints Hindi in one Devanagari face, Noto Sans Devanagari, regular or bold; there is no choice of Hindi typefaces.
- It does not add stickers, frames from a library or effects. It prints words, and checks them first.
Questions people ask
Is my photo uploaded?
No. The picture is decoded by your browser and the caption is drawn onto a canvas in this tab. The file you download is made in the tab too. There is no server here that accepts a picture.
Does the caption cover the photo?
Only if you choose it. A strip below or above adds a band to the picture and leaves every pixel of it visible; the band over the bottom and the meme layout print on the picture itself; the polaroid frame adds a white border with the caption in the wide bottom margin.
What size is the downloaded picture?
By default the picture's own size, plus the caption strip or frame. You can also save it sized for WhatsApp (long edge 1,600 pixels, JPG) or for an Instagram 4:5 post (1,080 × 1,350, the picture fitted inside).
Can I write the caption in Hindi?
Yes. Every typeface falls back to Noto Sans Devanagari, which this site serves itself, so a Hindi or mixed caption prints the same on every phone and computer — no Hindi font needs to be installed. If that file cannot load, the Devanagari face your system carries (Nirmala UI, Kohinoor Devanagari or Mangal) is used instead.
Why does it check my caption?
Because a caption has a job: it says what the picture does not — who, where, when, why it matters. The checker reads it as a caption, and if you also type the picture's alt text, it warns when the two are the same sentence, which a screen reader would read twice.
What does “embed the alt text” do?
It writes the alt text into the downloaded file's IPTC accessibility field (XMP), so a site that reads embedded alt text — WordPress 7.0 and later, for one — can pick it up when you upload the picture. It is not printed on the picture.
Where to take this next
- CaptionThe visible line under a picture, read back against the job a caption actually has.
- Embed alt textWrite alt text into a JPEG, PNG or WebP file's IPTC fields without touching the pixels.
- Alt textWrite the alt attribute yourself, with the picture open and the findings live.
- Alt text, caption and long descriptionThree texts beside one picture, three different readers, and what each one is for.