Quick reference tables you can actually use
Some questions come up over and over. What number is the letter A in ASCII? Which dialing code do you punch in to call Brazil? What's the MIME type for a .webp file, again? You could keep a browser tab open to a sprawling spec, or you could just look it up in a clean table and get back to work. That second option is what this page is about.
The reference collection on speedor.net gathers the lookups people reach for most: distances between cities, country codes (both ISO and dialing), MIME types, an ASCII table, the full periodic table, and a searchable emoji list. Everything loads in the browser, there's no sign-up, and there's nothing to install. You type, you scan, you copy the value you need.
Who reaches for these
Developers, mostly, but not only. A back-end engineer checking a Content-Type header, a student cramming for a chemistry exam, a traveller working out how to phone home, a writer hunting for the right symbol or accented letter, a support agent confirming a country's two-letter code for a form. Different jobs, same need: a trustworthy answer in a couple of seconds, without the clutter that surrounds most of these tables elsewhere.
The ASCII table
ASCII stands for the American Standard Code for Information Interchange. It's a 7-bit scheme that maps 128 characters to numbers, and it's been quietly underpinning computing since the 1960s. The first 32 codes are non-printing control characters — things like tab, newline, and carriage return — that once steered teletypes and printers. Codes 32 through 126 are the printable set: the space, digits, punctuation, and the Latin letters you're reading now. The table shows each character in decimal, hexadecimal, octal, and binary, which is exactly what you want when you're debugging an encoding problem or working out why a string sorts the way it does.
Country codes: ISO and dialing
There are really two systems wearing the same name. ISO 3166-1 hands every country a two-letter code (like DE), a three-letter code (DEU), and a numeric one — these are the codes that show up in domain names, currency tables, and database fields. Dialing codes are a separate thing, governed by the ITU, and they're what you actually type into a phone. To call abroad you string together an exit prefix (often 00 or, in North America, 011), then the country code, then the local number. Our country codes table lines all of these up side by side, so you don't have to cross-check three sites to fill in one form.
MIME types
MIME types — also called media types — tell software what kind of file it's looking at. When a web server sends a page, it includes a Content-Type header like text/html or image/png, and the browser uses that to decide whether to render, download, or play the thing. Get it wrong and your stylesheet won't load or your PDF opens as gibberish. Email leans on the same labels to attach files correctly. The fallback for plain text is text/plain, and when nothing else fits, software defaults to application/octet-stream — a polite way of saying "just download it." Our MIME types list pairs each type with its usual file extension so you can match one to the other in a glance.
The periodic table
The periodic table arranges every known element by atomic number — the count of protons in the nucleus. Read it left to right, top to bottom, and that number climbs by one each step. Columns (groups) gather elements with similar chemistry; rows (periods) track how electron shells fill up. Each cell carries the symbol, the name, the atomic number, and the atomic mass, which is plenty for homework, a lab calculation, or settling a quiz-night argument about which element is which.
Distances and emoji
The city distance lookup gives you the straight-line, as-the-crow-flies figure between two places in both kilometres and miles — handy for rough trip planning, shipping estimates, or just satisfying curiosity about how far apart two cities really are. And the emoji list rounds things out: a searchable grid for writers and chatters who want a specific face or symbol without scrolling an endless picker.
All of these are built to be fast and offline-style — small, focused tables that answer one question cleanly. No accounts, no pop-ups, no ten-second wait while an ad loads. Bookmark the ones you hit often and they'll be a tab away when you need them.
Frequently asked questions
What is ASCII and how many characters does it have?
ASCII is the American Standard Code for Information Interchange, a 7-bit code that maps 128 characters to numbers. Codes 0 to 31 are control characters, and 32 to 126 are printable letters, digits, and punctuation.
What is the difference between ISO country codes and dialing codes?
ISO 3166-1 codes are two-letter, three-letter, and numeric identifiers used in software and forms. Dialing codes are the numbers you type to phone a country, set by the ITU. They are separate systems, so our table shows both.
Why do MIME types matter?
A MIME type tells a browser or email client what kind of file it is handling, sent in the Content-Type header. The wrong type can stop a stylesheet, image, or PDF from loading correctly, so matching the right type to a file extension is important.
How do I read the periodic table?
Elements are ordered by atomic number, the number of protons, increasing left to right and top to bottom. Columns group elements with similar chemistry, and each cell lists the symbol, name, atomic number, and atomic mass.
Is the city distance the driving distance?
No, it is the straight-line or as-the-crow-flies distance between two points, shown in both kilometres and miles. It is a good estimate for planning but does not follow roads.
Do I need an account to use these tables?
No. Every reference table is free, needs no sign-up, and runs in your browser. You look up the value you need and copy it, with no clutter in the way.