Through vs. thru

Through and thru are different spellings of the same word. Thru is the less preferred form, however, and it might be considered out of place outside the most informal contexts. If you’re writing for school or for a job application, for instance, through is definitely the safer choice.

One exception: The shorter spelling is often used in drive-thru, where the term relates to getting fast food or banking without exiting one’s car. But though the shorter spelling has gained ground in this use, drive-through still prevails by a significant margin.

In current news publications that make content available online, thru only appears a tiny fraction of the time. We find only a few scattered instances of its use, against tens of thousands of instances of throughThru is certainly gaining ground in text-speak and social networking, and it may someday become the preferred spelling, but we’re not betting on it just yet.

The ngram below graphs the use of through and thru in a large number of English-language texts published from 1800 to 2019. As you can see, thru barely registers against through (though it has a brief spike around 1920, which we can’t explain).

Through Vs Thru English


The two men met through the Internet, fate and a 2008 BMW. [NY Times]

Meanwhile, the US itself exerts force on those same companies through antitrust suits. [Guardian]

He read through legal papers, as he generally does that time of day. [Washington Post]

Rudy Giuliani warned “it isn’t over” for enemies preying on America and said Republican Mitt Romney is the better choice to lead the country through precarious times. [National Post]

Officers say a woman came through the drive-thru, displayed a small handgun and demanded money. [KWCH]

A driver has taken the meaning of drive through literally today, slamming his car through the front of a shop. []

27 thoughts on “Through vs. thru”

  1. The spike for “thru” around the 20s may be connected to the inexplicable popularity of spelling words wrong on purpose. “OK” being what was left of “Oll Korrect” and so on.

    • Not necessarily. There is no definite consensus on the etymology of OK. Furthermore, “thru” was originally not a misspelling, to clear things up.

      • That’s because in a fast food setting with hungry customers “through” is a psychologically tedious word to paint on an advertising sign (since the mid 40’s). I believe in this aspect the writer is incorrect. The exception maybe fine dining establishments who use “drive-through” on menu print only.

  2. Houston Open of golf spells it “Thru 11 holes” etc on their leaderboards and I don’t think it’s because of space-saving. Surprising since golf is a sport built on tradition.

  3. I am an architectural technician and use it all the time in my specifications. i.e. “the M20 bolts go thru the whole timber deck width.”

  4. Similar to the architect – I am an engineer and ‘thru’ is almost exclusively used in notes on engineering drawings. E.g. “DRILL AND TAP M6 X 1.0 HOLE THRU”

  5. “Thru” is the primary spelling used on engineering and technical drawings, used in hole callouts and to define other features that exist through the entire part.

    I.E. “Ø.250 THRU” to describe a hole or bore that is .250in in diameter and exists through the entire part.

    • Yes, “thru” seems to be used in American English where British English would say “to” (“24 to 28 July”) or “until” (“until 28 July” or “from now until 28 July”).

      British English doesn’t use the spelling “thru” and doesn’t use “through” for ranges.

      • The word “thru” can also be used as a group subset of “to”. For example window ” 31 to 27″ will serve the last names of “L thru P”. See how it can serve to separate ” confusion” and it is also the explanation why “thru” is used in “technical” fields.

  6. Most popular reference, as in The star spangled Banner – US NATIONAL ANTHEM

    “Oh, say can you see,

    By the dawn’s early light,

    What so proudly we hailed,

    At the twilight’s last gleaming,

    Whose broad stripes and bright stars

    Thru the perilous fight,

    O’er the ramparts we watched,

    Were so gallantly streaming,

    And the rocket’s red glare ☆,

    The bombs bursting in air ★,

    Gave proof through the night,

    That our flag was still there

    Oh say does that star-spangled,

    Banner yet wave

    O’er the land of the free

    And the home of the brave!”

  7. Odd, I don’t believe I’ve ever seen “drive-thru” spelled any way other than what I just typed.

    Yet when writing in any other context, it is “through” for me 100% of the time.

  8. What about:
    I worked through all of the issues that were reported in order file the documents from day 30 thru day 45 as allowed.

  9. I’ve noticed old hymnals tend to favour “thru”, probably because “through” is a long spelling to fit on a single (often short) syllable when clarity is important and space at a premium. That could explain the spike in the 20s.

  10. I don’t care about the populairity of the word thru. I want to know if the word may be used by official English grammar rules. It says nothing about this matter. I’d expect at least that from a site called grammarist.

  11. History of the word “thru”, after doing some research I found out that the word “thru” is actually an acceptable business “jargon” that gained popularity during the industrial era. During factory and assembly changes in organizing workers the word “thru” was a lot easier to write on signs and not as busy on the “eye” as the word “through”. Window “7” will serve numbers “26” thru “38”. Later this system was adopted to the ” Drive up” restaurant experience as the server gave a number to the occupants of the vehicle and became known as a “Drive Thru” due to accuracy and number served “not necessarily ” movement or speed” at the time. Note that “through” outside of a business atmosphere is the correct term used.


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