A minimal PDF
Two identical pages carrying the bones of an invoice in plain shapes, and not a word of lettering: the smallest file there is, and it opens anywhere.
A page whose letters cost one byte each
A bank that prints two million statements a night pays for every byte twice over: once on the disc the run is kept on, once on the line it travels down. A letter is normally written into a file as a pair of bytes, because that is what it takes to reach any letter of any alphabet on earth. A statement in French needs a hundred or so of them, and the second byte is a nought on every single letter of the run.
Told to, the engine settles a number of its own for each letter a document uses, writes the list of them into the file so a reader knows what it is looking at, and then spends one byte a letter instead of two. The page shows the three lines drawn both ways and prints what each way came to, counted as the page was drawn. It ends on what the short way buys besides room: the space between words becomes something a document can widen, which is how justified text is set, and which the long way has no way of reaching.
What this example shows
- One byte a letter instead of two, on every line of the run.
- The file carries its own list of what each number stands for.
- The space between words becomes something a line can widen.
The code that writes it, in full
Whole programs, hundreds of lines long, for whoever writes your software. The third is not a program at all: it is a plain list of what the page has to say, which the service is sent.
Read the Rust source Read the Python source Read the JSON source
The document itself
What this document weighs
This document weighs 52.9 kB.
This figure is read off the very file the button above hands you, not from a table written down beside it. See what every document weighs.
The speed and weight figures on this site are measured with a licence key. See what a trial copy draws.
Details for technical readers
Exactly 52 879 bytes.
A kilobyte on this site is a thousand bytes.
Examples near this one
Showing page one before the file has arrived
The same document written twice, the ordinary way and with its first page moved to the head of the file, with how much of each a reader must hold before page one appears.
Making the file smaller
The same document written twice, plainly and packed, with what each one weighs and what the packing saved.
A document that reads freely and asks not to be copied
A page that opens with nothing typed and prints like any other, and that asks the reading software to leave its text where it is. Every word of it is scrambled inside the file.
A document that asks for a password before it opens
A page nothing shows until its password is typed in: no first line, no preview, no picture of it anywhere. The password is written on its own page, to be tried.
Fonts kept inside the file
Text set in a typeface the file carries inside it, cut down to the letters actually used, and still searchable, copyable and readable aloud.
Glossary
- byte
- The unit a file's weight is counted in, the way a parcel is counted in grams. A thousand of them make a kilobyte, and a million make a megabyte — the size of one photograph taken with a telephone. A one-page PDF here weighs between six thousand and a hundred and twenty thousand, so a hundred of them fit in the space of five photographs.
- justified text
- Text whose lines all stop on the same right edge, as in a newspaper column. Nothing is added to the words: the spaces between them are stretched, line by line, until the line reaches the edge. It reads well in a wide column and goes loose in a narrow one, where the stretched spaces open channels of white down the page.