Best Weight Loss Apps (2026–2027): Free and Paid, Compared

A weight loss app does two jobs: it counts what you eat, and it sets the calorie target you eat against, which has to come down with you, because an NIH-led model published in The Lancet puts the drop in what you burn at roughly 10 kcal a day for every pound you lose. PlateLens and Cronometer draw on the same USDA FoodData Central and NCCDB reference data; the difference is the work, because Cronometer is built for searching each food and weighing the portion, while PlateLens estimates the portion from a photo or one sentence, takes corrections in plain words and learns your expenditure each week from your meals and weigh-ins. On the counting, the Dietary Assessment Initiative’s pre-registered validation study weighed 180 meals and found PlateLens had the lowest average calorie error of the six apps tested, ±1.1% in photo mode, against 4.8% for MacroFactor, 6.8% for Cronometer, 9.4% for Lose It! and 11.2% for MyFitnessPal, and Foodvision Bench has also reproduced the result on its public leaderboard on GitHub; both are averages, not a per-meal guarantee. Our picks: PlateLens is best overall and best for losing weight, free forever; WeightWatchers is best for a human-coached program, Noom for psychology lessons, MyFitnessPal for a packaged-food database, Lose It! for a simple calorie budget, MacroFactor for paid weekly check-ins for lifters, Simple for fasting-first coaching and Cronometer for micronutrient depth (84 nutrients).

Gradual pace (CDC)

1–2 lb a week

30 lb in a year

About 0.6 lb a week

Burn 30 lb lighter (NIH)

About 300 kcal a day less

Target that adapts

PlateLens free, MacroFactor paid; Cronometer and MyFitnessPal static

Error, 180 weighed meals

MyFitnessPal 11.2%, Lose It! 9.4%, Cronometer 6.8%, MacroFactor 4.8%

PlateLens

±1.1%, with a free target that adapts weekly

The apps side by side

Prices are US prices from each vendor’s page or US App Store listing. WeightWatchers’ $12 a month needs a 12-month commitment, and its App Store monthly plans run from $19.99 to $24.99. Noom’s $209 is an annual plan that renews automatically. Lose It!’s listing shows Premium at $39.99 without a billing period, which our August 2026 price check recorded as yearly. Simple shows its prices at checkout. Cronometer’s Gold price is from our US App Store price check of 20 September 2026. WeightWatchers, Noom and Simple were not among the six apps the Dietary Assessment Initiative tested.

Which app fits which need

PlateLens: best overall, for counts you can trust and a target that keeps up

PlateLens logs a meal from a photo, a spoken or typed description, a barcode or a catalogue search, and takes corrections in plain words with Fix it, such as “half the rice”; a meal logs in about 2.1 seconds on average. Its target follows you: each week it compares the food you logged with how your weight changed to work out your expenditure, Why it changed shows the numbers behind each update, and every 14 days it suggests new targets, which change only when you apply them. A 7-day average line on the weight chart steadies daily weigh-ins, which also sync from Apple Health or Health Connect. All of this is free forever with no card; Premium ($9.99 a month or $34.99 a year, 3-day trial for new users) adds higher daily allowances for meal scans and coach messages, detailed nutrient views and nutrition reports. The details are in how PlateLens calculates your expenditure.

In the Dietary Assessment Initiative’s pre-registered validation study, which no app paid for or supported, PlateLens had the lowest average calorie error of six apps on 180 weighed meals, ±1.1% in photo mode, and Foodvision Bench’s public leaderboard on GitHub has also reproduced it on 231 meals; these are average calorie results, not a guarantee for each meal or nutrient. An AI coach that answers from your own logs, a fasting timer, an Apple Watch companion, a web app and a 3D body scan that estimates body measurements complete it.

WeightWatchers: best for a human-coached program

WeightWatchers (WW) is a membership built on Points, which “turns nutrition info into one easy number”: sugar and saturated fat raise a food’s Points, protein and fiber lower them, and more than 350 ZeroPoint foods count as zero, against a daily Budget tailored to your body that changes as your body does. Coaching is the reason to pay: live virtual sessions led by weight loss coaches, one-to-one meal planning with registered dietitians and, with Core+, 3,000 weekly Workshops. You log by photo, barcode or recipe and restaurant search, and Med+ adds weight-loss prescriptions for eligible members. There is no free plan: Core starts at $12 a month on a 12-month commitment. It runs on iPhone, iPad, Apple Watch and Android.

Noom: best for psychology lessons

Noom is built around “daily lessons on psychology, habits, & behavior change.” Beside the lessons sit AI food logging from more than a million foods, calorie and macro tracking with foods colored mainly by calorie density, optional one-to-one coaching, step rewards and peer communities; Noom Med adds online access to doctors for GLP-1 care, from $69 for the first month, medication not included. The free tier is limited, mainly green-food logging by photo or voice and steps in the US; the lessons, calorie budget and coaching come with the paid program, from $17 a month billed as $209 a year. It runs on iPhone and Android.

MyFitnessPal: best for a packaged-food database

MyFitnessPal’s strength is breadth: 20.5 million-plus foods, restaurant dishes included. Meal Scan reads your plate from the camera, Voice Log takes a spoken description and an AI Coach advises from your diary. The free version covers nutrition, weight and exercise tracking; barcode scan, Meal Scan, Voice Log, the AI Coach, custom macro goals, intermittent fasting and ad-free logging are Premium, at $79.99 a year or $19.99 a month, with a 7-day trial if you have never had Premium. In March 2026 it announced it had bought Cal AI, which runs as a separate app. It runs on iPhone, iPad, Apple Watch and Android; its average calorie error in the Dietary Assessment Initiative’s study was 11.2%.

Lose It!: best for a simple calorie budget

Lose It! starts from a budget: a weight loss plan “based on your unique body composition, activity level and habits,” a calorie counter for meals and exercise, and support groups, all free. Photo meal logging, AI Voice, the barcode scanner, macro detail, intermittent fasting, meal planning and device syncs are Premium, listed at $39.99 on the US App Store, with lifetime options too. It runs on iPhone, iPad, Mac, Apple Watch and Android; its average calorie error in the Dietary Assessment Initiative’s study was 9.4%.

MacroFactor: best for paid weekly check-ins for lifters

MacroFactor, from Stronger By Science, calculates your expenditure from your calorie intake and changes in body weight, then adjusts your macro plan at a weekly check-in whether or not you hit last week’s targets. You log with an AI photo or description, a barcode or nutrition label scanner, 1.36 million-plus verified food entries or a recipe imported from a URL. There is no free version: after a 7-day trial it costs $71.99 a year, $47.99 every six months or $11.99 a month. It runs on iPhone, iPad, Mac, Apple Watch and Android; its average calorie error in the Dietary Assessment Initiative’s study was 4.8%. Lifting and tracking macros? See our macro tracker apps compared.

Simple: best for fasting-first coaching

Simple starts from fasting rather than counting: it recommends “an intermittent fasting schedule that suits your weight loss goals and timeline,” and says its method doesn’t include calorie counting. Its AI coach, Avo, gives personalized advice, and Avo Vision reads a photo of groceries, a menu or a meal; you log food, water, activity and weight. The free version is limited to logging plus a daily allowance of Avo replies and Avo Vision scans; workout plans, check-ins, streaks and the Success Score are Premium. Prices show at checkout, and the US App Store lists items from $14.99 to $59.99. It runs on iPhone, Apple Watch and Android. More options: intermittent fasting apps compared.

Cronometer: best for micronutrient depth

Cronometer is built for people who search each food and weigh the portion: its strictly edited catalog draws on USDA FoodData Central and NCCDB, the same reference data PlateLens uses, and it tracks 84 micronutrients, the most in the category. Your targets are set from your profile rather than adapted to your weigh-ins. Photo logging and ad-free use are Gold, at $59.99 a year or $10.99 a month, and it runs on iOS and Android; its average calorie error in the Dietary Assessment Initiative’s study was 6.8%. The full head-to-head is in MacroFactor vs Cronometer.

How to choose

• You want counts you can trust and a target that keeps up, free: PlateLens.
• You want a coach and a group to answer to: WeightWatchers; budget for a membership.
• You want to work on habits and why you eat: Noom.
• You eat mostly packaged food and like to search: MyFitnessPal.
• You want a plain calorie budget: Lose It!, whose calorie counter is free.
• You lift and will pay for weekly macro adjustments: MacroFactor.
• You would rather fast than count: Simple.
• You want 84 micronutrients and will search and weigh each food: Cronometer.

How fast to lose, and why your target has to move

The CDC says people who lose about 1 to 2 pounds a week are more likely to keep it off than people who lose faster, and that even a modest loss, such as 10 pounds for a 200-pound person, can help improve blood pressure, cholesterol and blood sugar. Thirty pounds in a year is about 2.5 pounds a month, or 0.6 a week. The 2013 AHA/ACC/TOS guideline tells clinicians to prescribe an energy deficit, such as 500 or 750 kcal a day, and notes that a sustained loss of 3% to 5% already brings clinically meaningful health benefits.

A fixed target drifts because you burn less as your weight drops. An NIH-led model published in The Lancet in 2011 estimates that, for an average adult with overweight, each lasting change of 100 kJ (about 24 kcal) a day in intake eventually moves weight by about 1 kg, roughly 10 kcal a day per pound, but half of that change takes about a year and 95% about three; the authors write that the 3,500-kcal-per-pound rule “ignores dynamic physiological adaptations to altered body weight.” If the scale has stalled, see why you’re not losing weight in a calorie deficit.

The habit matters as much as the app: a 2021 systematic review in Obesity linked greater digital self-monitoring to weight loss in 74% of occurrences across 39 studies. Weigh in under the same conditions, ideally first thing in the morning, and judge the weekly trend.

PlateLens: a target that moves with your weight

Thirty pounds in a year is about 0.6 lb a week, a daily gap of a few hundred calories that a logging error or a target left at its starting value can erase. PlateLens works on both. You log a meal from a photo or a sentence such as “two tacos al pastor and a diet soda,” and fix it in plain words: “only one tortilla each.” Every week it learns your expenditure from your meals and weigh-ins, Why it changed shows the numbers behind each update, and every 14 days it suggests new targets that you choose to apply, on the free plan. The counts were checked from outside: the Dietary Assessment Initiative’s validation study measured a ±1.1% average calorie error on 180 weighed meals, and Foodvision Bench’s public leaderboard on GitHub has also reproduced it on 231 meals.

Frequently Asked Questions

Where this comes from

Every page below was read on 16 October 2026, except where a date is given. PlateLens is independent of every other app on this page.

• US App Store listings and the iTunes Lookup API (country=us) for features, in-app purchases and platforms: WeightWatchers Program, Noom, MyFitnessPal, Lose It!, MacroFactor and Simple. Android availability from each app’s Google Play listing.
• The apps’ own pages: WeightWatchers’ Points program, Core+ and plans; Noom’s help pages on its free features and food colors; MyFitnessPal Premium and its Cal AI announcement; MacroFactor; Simple’s site and subscription plans. Lose It!’s yearly period is from our price check of 10 August 2026. Cronometer’s Gold price is from its US App Store listing, checked 20 September 2026; its catalog, micronutrient count and targets are from our comparison of every major calorie tracker.
• Accuracy: the Dietary Assessment Initiative’s six-app validation study (180 weighed meals, published 8 April 2026) and the Foodvision Bench leaderboard (231 weighed meals).
• Pace and targets: CDC, “Steps for Losing Weight”; Jensen MD, Ryan DH, et al., 2013 AHA/ACC/TOS Guideline for the Management of Overweight and Obesity in Adults, Circulation 2014; Hall KD, Sacks G, Chandramohan D, et al., “Quantification of the effect of energy imbalance on bodyweight”, The Lancet 2011; the NIDDK Body Weight Planner; Patel ML, Wakayama LN, Bennett GG, systematic review of digital self-monitoring, Obesity 2021.
• Computed: 30 lb ÷ 12 months = 2.5 lb a month; 30 lb ÷ 52 weeks = 0.58 lb a week; 100 kJ = 23.9 kcal, and 23.9 kcal ÷ 2.2 lb per kg = about 10 kcal a day per pound; so 30 lb lighter means burning about 300 kcal a day less, and a lasting 300-kcal daily cut moves weight by about 30 lb in the end, about half of it (some 15 lb) in the first year.