Border Photo: add a border to any photoFrame every photo like a gallery print.

Space around a picture, given a number. Four edges, four units, and a readout that shows the arithmetic rather than hiding it.

Drop a photograph. Widths are measured against its long edge, so the fields below stay inactive until one is loaded.

Once a photograph is open, the rail gives each part of the border its own page — widths, fill, mat, corners, shadow, caption, recipes and output — and every figure stays editable.

JPG, PNG, WebP, AVIF, GIF, BMP and TIFF decode here. HEIC pulls a codec the first time it meets one.

The space around a photograph is a measurement before it is anything else. It has a width on each of four edges, those widths are expressed in some unit, and that unit has to resolve to whole pixels before a single byte can be written. Most tools that add a margin conceal all three of those facts behind a slider marked thin to thick. This one puts them in a rail and prints the result above the canvas.

Two intents arrive at this page and they want different things from it. One is presentation: a photographer or a printer wants a defined margin of a known size, usually white, usually even, sometimes weighted at the bottom the way a mounted print is. The other is fitting: a picture is the wrong shape for where it is going, and bars have to be added so that nothing gets cut off. The second is the larger job by a distance, and it is the one most competitors treat as an afterthought.

The first control asks what should stay fixed, and it is first because the answer decides what every other number on the page means. It used to be named after the mechanism — grow, inset, fit ratio — which describes what the code does rather than what you are choosing. Photo pixels fixed adds the border outside the picture: the photograph keeps every pixel it arrived with and the output file is larger by the sum of the two widths on each axis. Canvas fixed draws the border within the original dimensions, so the output matches the input and the picture is resampled smaller to fit the space that is left. Proportion fixed ignores the question of thickness and asks a different one: what shape should the finished frame be, and what should fill the difference. Pixels fixed goes one step further and names the exact output — 1080 by 1350 for an Instagram post, 640 by 640 for a WhatsApp DP — and contains the photograph inside it, reduced if it must be, never cropped, and never enlarged unless you tick the box that allows it.

Below that sit the unit and the resolution, in that order, because a width in millimetres is meaningless until the second field has a number in it. The figure is pixels per inch, whatever the file calls it. A printer’s own dots per inch is a different and usually much larger number — an inkjet laying down 1,440 dots per inch is describing its nozzles, not your picture — and neither figure says anything about how much detail the photograph actually holds. What this field does is decide how many pixels a millimetre is worth, and nothing else. The tool reads the JFIF density block of a JPEG, the resolution tags in its Exif block, and the pHYs chunk of a PNG, and it shows which one it found. When a file declares nothing, the field reads unset and the millimetre entry stays inactive — an assumed 72 or an assumed 300 would be a guess presented as a measurement.

The four edge fields come next, linked by default. Linked, one number drives all four and a weighting control lets the lower edge run between 1.1 and 1.3 times the sides, which is the convention a framer uses so that a mounted picture does not appear to be sliding down its own mat. Unlinked, each side is independent. Arrow keys move the focused field by one unit and Shift-arrows by ten; L toggles the link; and the button beside the measurement line hides the border for as long as you want it hidden, with Space as the quick glance for anyone who prefers a gesture.

JPG, PNG, WebP, AVIF and GIF decode through the browser’s own image pipeline on every browser this site supports. BMP, TIFF and ICO go through the same pipeline and are therefore at its mercy: Safari reads TIFF, Chrome and Firefox generally do not, and this site ships no TIFF decoder of its own — so a TIFF may simply be declined, with the reason named, rather than silently failing. HEIC — what a recent iPhone writes by default — needs a WebAssembly decoder that is fetched the first time one of them is opened and is absent from the page until then, so nobody who never opens a HEIC ever downloads it.

Four container details change what the tool says rather than what it does. A JPEG with four colour components is CMYK or YCCK; it is converted to sRGB on decode and the rail names the conversion. An animated GIF or WebP contributes its first frame, stated before you export rather than discovered afterwards. A source with an alpha channel keeps it, and the border is drawn in the colour you chose or left empty — it is never quietly flattened onto white. And the orientation flag is resolved before anything is measured, because a rotated frame changes which edge is the long one and therefore what a percentage means.

Guardrails are evaluated against the output, not the input, which matters here more than on most tools: a 24-megapixel photograph with a 60 mm margin at 300 DPI composites to well over 30 megapixels, and the ceiling that matters is the one the finished canvas has to clear. Past roughly 32 megapixels (16 on iOS) a lighter working copy is offered as a choice; past 100 (40 on iOS) the file is declined with the measured figure named.

Both are limits of the operation itself, not of this implementation.

• Padding a photograph into another proportion adds no information to it. The bars are inert: they carry no detail, and enlarging the result later enlarges empty colour along with the picture. The alternative — filling the frame instead — means cropping or enlarging, and both cost something. One loses the edges of the composition, the other softens the whole picture. This tool chooses the loss you can see and measure.
• The composite is redrawn and re-encoded, so an embedded colour profile does not survive it. Output is sRGB and a wide-gamut original is converted on the way in. Capture data and location tags do not survive either; the saved file holds pixels and the dimensions of those pixels, and nothing else. If either matters to the destination, keep the original alongside the bordered copy.

The export row offers PNG, JPG and WebP, and the choice is not cosmetic: it decides whether the bars can be empty and whether the photograph is compressed a second time on its way out. WebP is offered only once this browser has proved it can write one — several accept the request and hand back a PNG wearing the wrong name, so the tool encodes two pixels first and greys the option out if the answer comes back wrong.

A flat region compresses to near nothing in either format, so the border is never what makes the file heavy — the photograph is. That is why PNG is the default here and the wrong default almost everywhere else: a bordered picture is usually on its way to a printer or a frame shop, where one generation of loss is one too many. When the destination is a web page and the original was a JPG already, JPG out costs a second generation that nobody will see and takes most of the weight off.

Every route opens this workbench in a different starting state, because the first thing a visitor sees ought to match what they came for: a square pad, millimetres with the file’s resolution on screen, an exact Instagram or WhatsApp size, a white border with a check on the saved file, or a mat and frame band ready to edit.

• Add a white border to a photo →Pure or paper white, even or weighted, with the saved file checked for banding.
• Photo frame editor →Mat, keylines, a frame band and a shadow, every one an editable number.
• Instagram photo without cropping →The whole photo in 1080 × 1350, 1080 × 1080 or a 1080 × 1920 story.
• WhatsApp DP without cropping →The full photo in a 640 × 640 square, with the round crop shown.
• Square photo without cropping →Bars added until a photograph is square, with nothing cut away.
• Print border in millimetres →Millimetres first, with the resolution they are measured against on show.

The written notes go further into the arithmetic than a rail can. They are indexed on one page, and each of them answers a question the readout raises but has no room to settle.

• Measurement notes →Written notes on units, proportion, mats, film edges and the limit of a numeric border.

Decode, composite and encode all execute in the page process, so no request made by this site carries your photograph.