HI in Morse code is ···· ··, written as .... ... Four dots for H, two dots for I, with a three-unit letter gap between them. Six dots total. No dashes. It is the fastest two-letter word in the English language to send in Morse — a rapid six-tap sequence that sounds light and quick.
Letter Breakdown
- H —
....— four dots. The sixth most common letter in English (6.1% of text). Four dots in quick succession — fast, light, sounds like a quick "h" sound. - I —
..— two dots. The fifth most common letter (7% of text). Two quick taps.
Both H and I are all-dot letters — no dashes at all. This makes HI one of the easiest words to send at speed. Left-left-left-left (H), brief pause, left-left (I). In the Two-Button Practice mode, that is six left-button taps with a pause between the fourth and fifth. It can be sent in under a second at 20 WPM.
Use the Translator to hear HI played. Then try HI HI (the doubled version) and listen to the rhythm — eight dots, two dots, eight dots, two dots, with word gaps between. You will understand immediately why it became the Morse laugh.
Why HI Is Special in Morse Code
In amateur radio CW (Morse code on radio), HI — and especially HI HI — means laughter. It is the Morse equivalent of LOL. The convention dates to the earliest days of radio, when operators on air needed a way to convey humour over a medium that carries no vocal tone and no facial expressions.
The rapid dot pattern of HI sounds inherently light and playful. Doubled — HI HI — the rhythm becomes almost musical. When an operator makes a joke during a contact and the other station sends HI HI in return, the joke landed. No further explanation needed.
This is one of several traditional CW conventions that form amateur radio culture:
- HI HI — laughter
- 73 — best regards (standard farewell)
- 88 — love and kisses (used between friends on air)
- FB — fine business (excellent, good job)
- GM/GE/GN — good morning / evening / night
See the full list on the Abbreviations page.
HI vs HELLO — When to Use Which
Both are valid greetings. The practical difference:
HI (6 signals) is faster, lighter, and has the additional meaning of laughter when doubled. In radio contacts, HI is more natural — it does not interrupt the flow of a QSO (radio contact) the way a longer word might.
HELLO (13 signals) is more formal, more distinctive by ear, and better for learning because it contains mixed dot-dash patterns. You can read more in the HELLO in Morse code guide.
Learning H and I Together
H (····) and I (··) are both all-dot patterns, which makes them easy to learn as a pair. The only distinction is length: H has four dots, I has two. In audio, this difference is clear once you have heard them a few times — H sounds like a short machine-gun burst, I like two quick taps.
They appear in Lesson 1 of the Learn page — among the first letters any student learns. They are also in Quiz Level 1 alongside E and T. If you can pass Level 1 of the quiz, you can send and receive HI reliably.
The All-Dot Letters Group
H and I belong to a group of letters that use only dots — no dashes. Learning this group together builds speed on the simplest patterns:
- E —
.— one dot - I —
..— two dots - S —
...— three dots - H —
....— four dots
These four letters — E, I, S, H — are all pure dots at increasing counts. After 30 focused repetitions, most learners can identify all four instantly by ear, distinguishing them by the number of taps. This group also forms the S of SOS (···) — three of the most common letters in emergency Morse.
HI in Different Contexts
As a casual greeting on air: When you make contact with another station and want to open informally, sending HI before the standard exchange is perfectly acceptable and immediately establishes a friendly tone.
As a response to a joke: Send HI HI after anything amusing. Any CW operator worldwide will understand immediately.
As a learning exercise: HI is ideal for building dot speed. Because it is all dots, the only variable is how fast and how consistently you can tap. Time yourself — HI at 20 WPM should take about half a second. Practise in Two-Button mode until this is automatic.
In emergency contexts: HI is not an emergency signal, but H (····) is the first letter of HELP (···· · ·—·· ·——·). Knowing H cold means you are part-way to knowing HELP — read the HELP in Morse code guide for the full signal.
Building Speed With All-Dot Letters
H (····) and I (··) belong to the all-dot group — letters that use only dots. Along with E (·) and S (···), these four letters are the fastest group to learn and the most useful for building raw dot-sending speed.
Practising this group in the Two-Button mode is pure left-button work — no right button involved. You can focus entirely on timing consistency: are your dots all the same length? Are your letter gaps (three dot lengths) clearly distinguishable from your intra-letter gaps (one dot length)?
A common exercise: practise sending EISHEISH (E, I, S, H, E, I, S, H) in sequence until the timing is perfectly consistent. Then increase the speed. This builds the foundational dot control that carries over to every other letter.
Speed target: at 15 WPM, a single dot is 80 milliseconds — the duration of a quick intentional tap. H (four dots) takes about 480ms total including intra-letter gaps. HI takes about 720ms. At 20 WPM, halve those numbers. Once HI feels slow at 15 WPM, you are in the range of comfortable on-air operation.
HI HI in Real Amateur Radio Contacts
HI HI has been part of Morse radio culture for over a century. Before the internet, before text messaging, before emoji — radio operators developed their own shorthand for human interaction. HI HI was the answer to the problem of conveying amusement over a purely tonal medium.
The convention is still alive. In any CW contest or casual contact, HI HI appears regularly. Foreign operators who may not share a spoken language with you still know what HI HI means. It transcends language the same way the underlying Morse code does.
Other emotional shorthand in CW culture: FB (fine business — used like "excellent"), GM/GE (good morning / evening), GL (good luck, often used at contest start), TU (thank you). These are covered in full on the Abbreviations page.
For anyone interested in getting licensed and using these conventions on air: the Ham Radio Morse Code guide explains the complete path from beginner to first contact, including how to respond to a CQ call and what to expect from your first QSO.
The Broader Significance of Dot-Speed
H and I are all-dot letters, which makes them useful for a purpose beyond just the words HELLO and HI: they are the standard tool for testing and building your maximum dot-sending speed.
CW operators talk about their "fist" — the personal rhythm and style of their Morse sending. A good fist has consistent timing, clear dot-dash distinction, and clean gaps. Building a good fist starts with dots, because they are the simplest element. If your dots are inconsistent, everything else is inconsistent too.
Practise sending HEHEHEHE (alternating H and E) at increasing speeds. This forces you to maintain consistent four-dot and one-dot patterns with proper three-unit gaps between them. When you can do this accurately at 20 WPM, your dot timing is solid enough for anything else in the alphabet.
The Two-Button mode lets you do this in software. Set the speed to something slightly uncomfortable, send HEHE sequences, and let the system flag your timing errors. When error rate drops below 10% at a given speed, increase by 1 WPM. This incremental method is how operators build reliably from 10 to 20+ WPM without developing bad habits.
HI as an Entry Point to Amateur Radio Culture
Amateur radio has a culture built over more than a century of operator interaction. HI HI is one of its oldest conventions — a relic of early radio that survived because it was genuinely useful and because it was fun. Learning it is not just about the pattern; it is about joining a tradition.
The culture of CW (Morse code on radio) is notably friendly to newcomers. Experienced operators remember learning themselves and most actively welcome beginners. Sending QRS (please slow down) at the start of a contact is completely normal and respected. Receiving a HI in reply to your first joke means you have successfully participated in a century-old communication tradition.
The Ham Radio Morse Code guide covers the full path from where you are now — knowing HI and a few other letters — to making your first on-air contact. The equipment required is modest, the licence exam is straightforward, and the community is welcoming. Many people who start learning Morse code for curiosity find themselves licensed within a year.
For a reference of all the cultural conventions — HI HI, 73, 88, FB, GL, and dozens more — the Abbreviations page is the complete guide.