Trendline is an iPhone app that reads Apple Health. Everything below assumes an iPhone; the escape route it describes is Apple Health, which Android does not run.
Two different complaints, one root
Spend an evening in scale owners' forums and the frustration sorts cleanly by price tier.
Premium scale owners are frustrated by the graph itself. When Withings redesigned its app, long-running community threads formed asking for the old weight graph back — readings folded into averages, less visible day-to-day resolution (r/withings, 2022, still active years later). Garmin Connect owners maintain threads about a weight chart whose fixed axis renders months of change as a nearly flat line (Garmin forums). These are documented product decisions users publicly dislike — not broken hardware.
Budget scale owners are frustrated by everything around the graph. The recurring, verifiable themes: apps that require an account before showing your own weight, readings that sync only while the app is open, data confined to one "main user," and apps that have shipped ads or subscription tiers on top of hardware you already paid for. The per-app pages linked below cite each behavior to its vendor documentation or App Store listing.
Why the companion app can't be the fix
None of this requires assuming bad intent. A scale maker's app is a hardware companion: it exists to pair devices, run firmware updates, and present every product the company sells. Weight display is one tile among many, built once for a whole product line. The observable consequences:
- The graph is a feature checkbox, not the product. Statistical care — smoothing that resists one odd morning, honesty about sparse data — is rare in this category, and complaints about naive graphs are common.
- Your reading history lives wherever the app keeps it. When a scale app is discontinued, that window can close: QardioBase owners lost app access when the company's services shut down in 2025 (Technodabbler's account), and ABYON owners found the app simply gone from the App Store (Apple Support Communities).
- Switching scale brands means starting a new history in a new app, because each companion app is a silo.
In our judgment — and this is an opinion, offered plainly — the scale you researched and paid for deserves better software than a bundled companion app is structured to provide.
The neutral store you already own
Every iPhone ships with a neutral, vendor-independent home for body measurements: Apple Health. Most scale companion apps can write to it — that is the one job nearly all of them do agree to do. Once a reading lands in Apple Health, three things become true:
- It outlives the app that wrote it. Readings stay in Health even if the vendor's app is deleted, discontinued, or replaced. (This is exactly what rescued the histories of owners who enabled Health sync before their scale's app disappeared.)
- It outlives the scale. Change brands next year and your history continues in one place — the new app appends to the same record.
- Any Health-reading app can present it. You are no longer limited to the bundled window.
One honest boundary: Apple Health stores a specific set of body metrics — weight, body-fat percentage, lean mass, BMI, height, waist. Body weight is the type virtually every scale app writes, which is why it's the reliable common ground. Composition extras vary by vendor, and some numbers on your scale's display (visceral fat, body water) have no Apple Health type at all — the per-scale pages below state exactly what transfers for each brand.
What a real trend view does differently
Getting readings out of the silo is half the fix. The other half is reading them with statistical respect: a single morning's weight is dominated by water, food in transit, and timing — accurate and still noisy. A trend view worth trusting smooths deliberately, resists one odd reading, and says so when evidence is thin instead of drawing a confident line through sparse data. The math Trendline uses for this is public, on the methodology page.
Find your scale
Each page below states, with sources: how that scale's readings reach Apple Health (exact steps), what transfers and what doesn't, known failure modes, and what to do when sync misbehaves.
- Renpho — two apps with confusingly similar names; which one, and what syncs
- Etekcity — the VeSync path
- eufy — why readings arrive only when the app is open, and the one-user limit
- Withings — good sync, with one manual-refresh catch
- Fitbit Aria — no direct path today; the honest workarounds
- Garmin Index — cloud-first sync and its delays
- Fitdays — the app behind Bveiugn, Healthkeep, Lepulse, and many more
- OKOK International — the Chipsea white-label app
- Yolanda, Feelfit & FITINDEX — three apps, one maker
- My scale's app is gone — ABYON, Qardio, and other orphaned hardware
- Wyze Scale — authorize once; check what actually transfers
- Xiaomi — two generations, two different apps; don't mix them up
- Omron — select scales only; better known for blood pressure
- Amazfit — the thinnest vendor documentation; what's actually verifiable
- iHealth — sync via MyVitals, account required
- Weight Gurus — the Greater Goods path
- No app at all? — the three setups that work without one
If your scale can't sync at all
Some scales have no Apple Health path — and a scale that only shows a number on its display is still a working instrument. You can add a weight reading to Apple Health by hand, and it becomes a first-class part of your history, identical in standing to a synced one.
When Trendline launches, it will also accept manual entries directly — including composition values Apple Health has no type for, like visceral fat and body water. Until then, the free weight trend calculator reads pasted weights right now, in your browser, nothing uploaded.
Try the idea
Paste a few weeks of weights into the weight trend calculator — from any scale, any app, or a notebook — and compare the raw series against a deliberately slower signal. That contrast is the whole argument of this page, made with your own data.
Sources
- r/withings: "New app update awful" (2022 redesign thread)
- Garmin forums: changing the scale of the weight graph
- Technodabbler: what happened to Qardio
- Apple Support Communities: ABYON app no longer in the App Store
- Apple: view your health data on iPhone
Trendline is not affiliated with or endorsed by any scale maker named on this page. Vendor behaviors change; this page states what was verifiable on the review date above, and each linked scale page carries its own verification date.