Why Is It Called Slack? A Code Name That Stuck

The origin: a dead game and the tool that outlived it

Slack was not designed as a product name. It was a placeholder for an internal tool at a company that was, at that moment, shutting down the thing it had spent years building. Every decision below was made under conditions no naming brief describes.

1. 2011: Tiny Speck ships a game called GlitchButterfield’s company launches Glitch, a browser-based multiplayer game, on 27 September 2011, then pulls it back into beta that November. To build it, the team runs its own chat tool.
2. November 2012: the game is called offGlitch will not work as a business. The shutdown is announced in mid-November and the servers go dark on 9 December. What survives is the internal tool, which the team keeps using for want of anything else to talk in.
3. 14 November 2012: “a better code name”That same week, Butterfield proposes replacing the tool’s codename, “linefeed”, with “Slack”. He published the chat screenshot years later, which is how the exact date is on the record.
4. The name was supposed to be temporaryIn one early employee’s account, Butterfield floats the word while making a gesture as though loosening a string between his fingers, and adds that they can find a better name later. They never did.
5. 2013 to 2014: the placeholder eats the companySlack opens wider on 14 August 2013, called a “preview” rather than a beta, and takes roughly eight thousand sign-ups in a day. It leaves preview on 12 February 2014; Tiny Speck renames itself Slack Technologies that August.

Note the proximity: the message proposing the name is dated 14 November 2012, and the press reported Glitch’s shutdown the next day.

Does Slack stand for anything? Yes, and that is the rare part

The company gives the expansion as Searchable Log of All Conversation and Knowledge. A variant swapping “Conversation” for “Communication” circulates almost as widely, so if you have seen both, that is why. What matters is the ordering, which Butterfield stated in public: asked which came first, he said he was pretty sure the word did, adding that the phrase was there at the beginning. That sits between the two things people mean by “acronym”.

• Not a true acronymA true acronym is assembled from the phrase: the initials exist first and the word falls out of them, as with IKEA’s founder, farm and village. Nobody wrote out the Slack phrase and noticed it spelled a word.
• Not a false backronym eitherThe usual case, the one most naming pages exist to correct, is a phrase invented by outsiders and pinned on a name that never meant it. adidas has two. Slack’s expansion is not folklore: the founder confirms it.
• A real backronym, fitted earlyThe word came first and the phrase was built to fit it, at the start rather than a decade later. Genuine, retrofitted, and disclosed.

The contrast with why is it called adidas is the cleanest in this set: that page exists to kill an invention, since “All Day I Dream About Sports” was never true, and this one exists for the opposite reason. Both point at one fact. A name with no obvious explanation will attract one, and the only question is who writes it. The case for initials is in should your brand name be an acronym.

Reclaiming a negative word: the mechanism nobody recommends

Free-associate on “slack” before 2013 and you get slacking off, slackers, cutting someone some slack. The register is idleness, a strange foundation for a tool sold on getting more done. Naming convention says avoid it, and the convention is usually right.

There is another sense, and the only contemporaneous hint at which one was meant is physical rather than stated: in that early employee’s account, Butterfield floats the name while making a gesture like loosening a string between his fingers. Slack in a rope is not laziness, it is give, the room a system needs so it does not snap.

What the record shows is that it stopped mattering. Once a word is typed by millions of people every working day in one context, the context wins. Founders draw the wrong conclusion from this: that any word can be reclaimed. Meaning is soft. The other properties of a common word are not. Set it beside why is it called Amazon, which borrowed a word for what it already evoked, the largest river on earth. Slack borrowed one in spite of what it evoked.

1. Phonetics: one syllable, one honest flaw

Say it: slack. One syllable, five letters, and no argument about where the stress falls. Heard once it types straight back out, with no fork between two plausible spellings. That is close to the ideal shape for a product people say aloud dozens of times a day, and it survives becoming a verb: colleagues say “slack me” within a week.

The one honest flaw is the opening cluster. Spanish and several other languages do not permit an s-plus-consonant onset, so speakers insert a vowel and it arrives as roughly “eslack”.

2. Memorability: the dictionary-word tax, itemised

Here the analysis has to hold its nerve against a very famous logo. Scored as a fresh candidate, “Slack” takes the full dictionary-word ding: the string sat in every English dictionary and rigging manual before the product did, so the brand borrowed an occupied slot rather than minting one. What keeps it out of the lower bands is the tension a work tool called “not working” carries, because small jokes stick where bland words do not. The traits that work without a joke are in what makes a brand name memorable.

The bill arrives in three places. Distinctiveness: a common adjective does not separate from competitors the way a coinage does. Search: queries returned rope, economics and idleness, so the company had to outrank the language itself. Domains: five-letter English words in daily use were registered on every extension in the 1990s, so slack.com was never free to register, and whatever happened next was an acquisition rather than a registration. Figures circulate for the cost, but they trace to a domain-trading forum rather than anything verifiable, so this page does not repeat them. The lesson holds without the number: if your name is an ordinary word, budget for buying the domain, as in your dream .com is taken.

3. Cross-language: the awkward reading was in English

The check finds no flags in the languages checked: nothing rude, no diacritics to lose in transit, nothing unfortunate when the word is clipped. The honest phrasing is no flags in the languages checked, never a blanket “safe”, because no automated pass clears every dialect and slang register on earth.

The instructive part is where the risk sat. Founders run these checks braced for the foreign market where their name turns out to be a swear word. Slack’s one loaded reading was in its home language, in front of its first customers. Outside English it arrives as an opaque sound, so the name is more neutral abroad than at home.

• Start with your own languageWrite down what your name means to a fluent speaker of the language you are launching in, slang included, before the foreign-language pass rather than after.
• Test the meaning against your promiseA negative word is survivable. One that contradicts your core claim is a headline waiting to be written. Ask what a hostile reviewer would do with your name and its dictionary entry together.
• Then check the sound abroadMost cross-language problems are heard, not read. Have a speaker in each market say it cold.

The full method is in the cross-language safety checklist.

The Namoly Report simulation: “Slack”

Here is how “Slack” performs against the four weighted checks, scored as a fresh candidate rather than on the company it became. The overall is the weighted mean, using the canonical weights (domain 0.30, memorability 0.25, phonetics 0.25, cross-language safety 0.20).

• Global Namoly Score61 / 100Good
• ReadabilityHighOne syllable, spells itself
• Linguistic safetyMediumNo flags in the languages checked

1. Domain availabilityweight 0.30The structural weakness, and it is not close. A five-letter English word in daily use had an owner on every extension long before 2012, so the exact match was never available to register. It could only be bought: a budget line, not a lookup.44Fair
2. Memorability & distinctivenessweight 0.25The dictionary-word caveat applies in full: the string is familiar and almost impossible to own alone. What rescues it is the tension. A word meaning “not working” on a tool for working is an odd pairing, and odd pairings stick.58Fair
3. Phonetics & readabilityweight 0.25One syllable, no stress to argue about, and it spells itself back after one hearing. The single flaw is the opening “sl” cluster, which speakers of Spanish and other languages break with a vowel, so it arrives nearer “eslack”.82Strong
4. Cross-language safetyweight 0.20No flags in the languages checked: nothing rude, no diacritics, nothing unfortunate when it is clipped. Medium rather than high for an unusual reason: the awkward reading is not in a foreign language, it is in English, where the everyday sense is laziness.66Good
5. Overall Namoly Scoreweighted meanExcellent in the mouth, costly on the ledger. A one-syllable word anyone can say, spell and turn into a verb, weighed down by an exact match never obtainable for free and a string the brand could not distinguish itself with. The company’s success is not evidence the name was cheap.61Good

• Strong80–100Short, distinctive, sticks after one exposure.
• Good60–79Solid and workable; minor trade-offs.
• Fair40–59Usable but forgettable or hard to spell.
• Weak0–39Reconsider; friction outweighs the upside.

Illustrative analysis for education. Every number in a real report ships with a justification, a confidence signal, and a tip. Not checked here: trademark and social-handle availability.

What founders can take from a code name that stuck

You are unlikely to be naming a chat tool while shutting down a video game, but the decisions underneath are ordinary enough to reuse.

• Meaning is negotiable, cost is notDaily use rewrites what a name evokes, which is how a word meaning “not working” ended up on a work tool and won. What use will not do is make the word cheaper to buy or easier to find.
• Common words are memorable and unownable at onceTwo questions, and founders keep answering them as one. Anybody can remember “slack”. Nobody could have owned it in 2012 without paying an incumbent, and searches still compete with the ordinary verb.
• Check whether the risk is in your own languageCross-language checks look outward by habit, at the foreign market where a name lands badly. Here the loaded reading sat in English the whole time. Check the language you already speak.
• A backronym is a joke you can only afford afterwardsThe acronym works because the word already worked. Reverse the order and you get initials assembled to spell something, leaving a string nobody can say. Earn the word first.
• Codenames become namesThe placeholder you type five hundred times before launch is the one that survives, because switching costs rise daily. Pick working names you would not mind keeping.

This was Butterfield’s second company built from a failed game. The first was Flickr, salvaged from Ludicorp’s Game Neverending, and he named it the opposite way: a misspelled coinage, distinctive and ownable and permanently in need of “no E”. Two names that fail and succeed at exactly the things the other does not. When a dropped vowel is worth the spelling tax is in should you misspell your brand name; the checks that settle it are in how to test a brand name.

Frequently asked questions

Why is it called Slack?

Slack is an ordinary English word that Stewart Butterfield picked on 14 November 2012 as a code name for the internal chat tool his game company, Tiny Speck, had built for itself, replacing an earlier codename, “linefeed”. It was meant to be temporary, was never replaced, and the company renamed itself Slack Technologies in August 2014.

What does Slack stand for?

Slack Technologies gives the name as an acronym for “Searchable Log of All Conversation and Knowledge”, and a variant using “Communication” circulates widely. Butterfield has confirmed the acronym is genuine, and has also said the word came first.

Is Slack a backronym?

Yes, by the founder’s own account. Asked publicly which came first, Butterfield said he was pretty sure the word did, adding that the phrase was there at the beginning. It is a real backronym: the company genuinely uses the expansion, but the word was chosen before the phrase existed.

Who founded Slack, and did it come from a video game?

Stewart Butterfield, with the Tiny Speck team, and yes. Slack began as the internal messaging tool built while the company was making Glitch, a browser-based multiplayer game that launched in September 2011 and shut down on 9 December 2012. It was the second time Butterfield turned a failed game into a business: he co-founded Flickr out of Ludicorp, whose Game Neverending was shelved when a photo-sharing side tool proved better.

Is Slack a good brand name?

By the four checks it is easy to say and expensive to own. It is one syllable, spells itself, and raises no flags in the languages checked. It is also a common dictionary word, so it is hard to distinguish and hard to search for, its exact-match .com was never available to register, and its everyday English sense is laziness. Good rather than Strong.

How was this score calculated?

The numbers here are illustrative, built from the same four checks Namoly runs on any name: domain availability, memorability, phonetics, and cross-language safety. The overall is the weighted mean, using the canonical weights (0.30, 0.25, 0.25, 0.20). Trademark and social handles are not checked.