Synched or Synced: Which Is Correct?
Here is a spelling question with a trick in it: synched and synced are both correct — but they are not interchangeable, because they are the past tenses of two different verbs. Synced is the past tense of sync; synched is the past tense of synch. Mix the pairs up — write “synched” when your verb was “sync” — and you have made the one real error this topic offers. This article sets out what the dictionaries actually record, so you can pair each past tense with its proper verb and never hesitate again.
The short version for the impatient: sync → synced is the standard modern pairing, and it covers nearly everything you will ever write about phones, files, and playlists. Synch → synched is the less common pairing, built on the alternative spelling synch. Pick the base verb first; the past tense follows automatically.
Two Verbs, Two Past Tenses
The confusion exists because English kept two spellings of the clipped form of synchronize: sync and synch. Each is a verb in its own right, and each forms its past tense regularly — by adding -ed to its own base:
| Base verb | Standing | Past tense / past participle | Example |
|---|---|---|---|
| sync | Standard, dominant modern form | synced | “She synced her phone to the laptop.” |
| synch | Recorded alternative, less common | synched | “The band synched their moves to the beat.” |
That table is the whole grammar of the question. The error people actually make is not choosing the “wrong” past tense in isolation — it is crossing the pairs: writing synched as though it were the past of sync, or synced as the past of synch. Keep each past tense with its own verb and the problem disappears.
What the Dictionaries Actually Record
Each piece of the table is documented:
- Sync → synced. Collins’s conjugation tables are explicit: present simple “I sync,” past simple “I synced,” past participle “synced.” The present participle is syncing. This is the form behind every “Syncing…” progress bar and every “last synced” timestamp you have ever seen.
- Synch is a real verb too. Merriam-Webster’s word data lists synch as both noun and verb — it is not a typo that slipped into print, but a recognised entry. Wiktionary-derived references describe synch as an alternative form of sync (noun and verb), and WordHippo puts it plainly: “Synch is an uncommon spelling of sync.”
- Synched = past tense of synch. The same references give synched as the past tense and past participle of synch, exactly parallel to synced from sync. The -ing form likewise has two spellings: syncing (standard) and synching (alternative).
Notice what no dictionary does: none of them calls synched “wrong.” The honest statement — and the one this article is built on — is that neither past tense is an error; they simply belong to different base verbs, one of which is far more common than the other.
The Matching Rule
The practical rule follows directly from the dictionary facts. Before you write the past tense, check which base verb is in play — usually your own document tells you:
- If you wrote (or would write) sync — “we need to sync the files” — the past is synced: “we synced the files.”
- If you wrote (or would write) synch — “we need to synch the files” — the past is synched: “we synched the files.”
The same discipline applies to every verb-form pair in English: the inflected form must be built on the base form you actually chose. The complete/completed pair works the same way — completed is only correct because it is built on the verb complete, and the choice of base form always comes first.
In practice, this means synced wins by default. Since sync is the standard modern spelling — the one in software menus, manuals, and nearly all edited prose — its past tense synced is the form you will need in the overwhelming majority of cases. Reserve synched for the rare occasions when you have deliberately chosen the synch spelling, and keep the pair consistent from the first verb to the last.
Pronunciation and the “-ing” Forms
Both verbs are pronounced /sɪŋk/ — “sink.” The past tenses add a /t/ sound: synced and synched are both pronounced “sinkt,” which is precisely why the spelling question has to be settled on paper rather than by ear. The homophone is worth a passing note: “sinkt” is also how sinked would sound — but that is a different verb’s problem, not this article’s.
The -ing forms follow the same two-track pattern: syncing (standard; “Syncing your library…”) and synching (the alternative spelling’s form). Match them to their base verbs exactly as with the past tense.
Correct vs. Incorrect
- ✓ “He synced his phone to the laptop to transfer the photos.” (standard pairing)
- ✓ “Our cloud storage automatically syncs your files to all your devices.” (present tense of sync)
- ✓ “The dancers synched their routine to the music.” (consistent synch/synched pairing — less common, but correctly matched)
- ✓ “Make sure your devices are synced before you leave.” (past participle of sync)
- ✗ “We need to sync the calendars, so I synched mine this morning.” → ✓ “…so I synced mine this morning.” (crossed pair — the base verb is sync)
- ✗ “The files have synched successfully.” (in a document that uses sync elsewhere) → ✓ “…have synced successfully.”
- ✗ “I syncronized the data.” → ✓ “I synchronized the data.” (the full verb keeps its hron; don’t blend the clipping with the original)
Common Mistakes
1. Declaring “synched” simply wrong. It isn’t — it’s the regular past tense of the recorded verb synch. The careful correction is narrower: “synched” is the wrong past tense for the verb sync. Precision here is the difference between a useful correction and a false one.
2. Crossing the pairs mid-document. “Sync your device, then check what synched” mixes the two families in one sentence. Whichever base spelling you choose, carry it through every form: sync, syncs, synced, syncing — or synch, synchs, synched, synching.
3. Writing “synched” out of habit from “synchronized.” Some writers add the h because the full verb synchronize has one. But the clipping sync dropped the h along with the rest of the syllables — its forms are synced and syncing, no h in sight.
4. Doubling the ending: “syncheded,” “synceed.” The past marker is added once: sync + ed = synced. There is no second helping.
5. Assuming the noun phrase follows the verb you chose. The set phrase is overwhelmingly written “in sync” (“the dancers were in sync”) in modern usage. If you have committed your document to the synch spelling throughout, “in synch” is the consistent choice — but for most writers, “in sync” is the form to use.
Frequently Asked Questions
Is it “synced” or “synched” for a phone backup?
Synced. Technology writing universally uses the sync spelling — “Syncing…”, “Last synced” — so the past tense is synced: “I synced my phone last night.”
Is “synched” ever the better choice?
Only when you have deliberately chosen the base verb synch. Some writers prefer synch in non-technical senses (music, dance, film — “synching the dialogue to the picture”), and there the matching past tense is synched. If you haven’t made that deliberate choice, default to sync/synced.
What about “syncing” vs “synching”?
The same two-track rule: syncing is the standard present participle (of sync); synching is the alternative form’s participle (of synch). Match the -ing form to whichever base spelling you are using.
Is there a related article on “synch vs sync”?
Yes — Clarifyra already covers the base-form question in Synch vs Sync: What’s the Difference and Which Is Correct?, which explains why both base spellings exist and why sync dominates modern use. This article answers the narrower question the base-form article leaves open: which past tense belongs to which verb.
Why does “synced” look odd — shouldn’t it be “synceed” or “syncked”?
English past-tense formation just adds -ed to the base: sync + ed. The c already carries the /k/ sound, so no extra k is needed (compare picnic → picnicked, where the k is added because the base ends in c before a vowel — sync ends in a consonant cluster, so no repair is required).
The Takeaway
Synced is the past tense of sync; synched is the past tense of synch. Neither is wrong in itself — the only mistake is crossing the pairs. Since sync is the standard modern spelling, synced is the form you will reach for in nearly all writing, from phone backups to project updates. Choose your base verb, match its past tense, and stay inside one family from the first sentence to the last.
