Albertyw.com

Airliner Identification

November 14, 2026

How to tell common Airbus, Boeing, and Embraer airliners apart from the outside without any special tools or knowledge. Start with the general type, then use the tables to narrow down to a model and variant. Door and exit layouts can vary between airlines; when a clue is ambiguous, use several clues together.

Quick Key

How many engines?
|
+-- 4 engines
|   +-- Two full-length decks of windows ..................... A380
|   +-- Hump only at the front of the fuselage ............... 747
|   +-- Single deck .......................................... A340
|
+-- 2 engines on the rear fuselage, T-tail ................... 717
|
+-- 2 engines under the wings
    +-- One aisle (narrow body), 2 main wheels on each side
    |   +-- Tires visible in belly, triangular fin at tail base ... 737
    |   +-- Rounded nose, notched rear cockpit window ............. A320 family
    |   +-- 4 cockpit windows, long pointed nose, flat tail cone .. A220
    |   +-- Small and slim, 4 cockpit windows, pointed tail cone .. E-Jet
    |
    +-- One aisle, 4 wheels on each side, tall gear, long and thin  757
    |
    +-- Two aisles (wide body)
        +-- 6 wheels on each main gear
        |   +-- Blade-shaped flat tail cone, no winglets ........ 777
        |   +-- Black "mask" cockpit windows, curved winglets ... A350-1000
        +-- 4 wheels on each main gear
            +-- 4 cockpit windows, sawtooth engine rear, no winglets  787
            +-- Black "mask" cockpit windows, curved winglets ....... A350-900
            +-- Notched rear cockpit window, bulge under wing ....... A330
            +-- Like an A330 but with a smooth belly ................ A300, A310
            +-- Pointed nose, tail ends in a cone, shorter ......... 767

Airbus vs Boeing

Feature	Airbus	Boeing
Nose	Rounder, blunter nose	More pointed nose (except the 777 and 747)
Cockpit side windows	Rear-most side window has a notched top rear corner (A320, A330, A340)	Straight-edged windows, often V-shaped lower edge
Wing strobes (night)	Double flash	Single flash

Boeing

Model	Variant	Length	How to identify
717		124 ft	Two engines on the sides of the rear fuselage; T-tail; larger with a rounder nose than regional jets with the same layout, such as the CRJ
737	All		Narrow body; main gear bays have no doors over the wheels, so after takeoff the retracted tires show from below as two dark circles in the belly; triangular fin at the front base of the tail; engines hang low under the wing
737	Classic (-300, -400, -500)	102-120 ft	Smaller wings, usually no winglets; small engines with flat-bottomed nacelles; now rare in passenger service
737	NG (-700, -800, -900)	110-138 ft	Flat-bottomed oval nacelles with a straight rear edge; blunt tail cone; blended winglets, split scimitar winglets (pointed tips), or none
737	MAX (7, 8, 9, 10)	117-144 ft	Round nacelles with a sawtooth rear edge; long pointed tail cone; split winglets with flat, square tips
737	-700 / MAX 7	110-117 ft	One overwing exit on each side
737	-800 / MAX 8	130 ft	Two overwing exits on each side; MAX 8-200 adds an extra exit behind the wing
737	-900ER / MAX 9	138 ft	Two overwing exits plus an extra exit or door plug between the wing and rear door, visible as uneven window spacing
737	MAX 10	144 ft	Longest 737
747	All		Four engines; hump at the front of the fuselage containing a partial upper deck
747	-100, -200	231 ft	Short hump with few upper deck windows; no winglets
747	-400	231 ft	Stretched hump; upright winglets (except the -400D)
747	-8	250 ft	Even longer hump; no winglets, but long raked wingtips that continue the wing sweep; sawtooth engine nacelles; freighters keep a short hump
757	All		Long, thin narrow body; tall landing gear with 4 wheels on each main gear; sloped “dolphin” nose
757	-200	155 ft	Usually two overwing exits, with no extra door between the wing and rear door
757	-300	179 ft	Very long; extra door behind the wing with about a dozen windows between it and the rear door
767	All		Small wide body; pointed nose; 4 wheels on each main gear; tail ends in a cone
767	-200	159 ft	Short and stubby for a wide body
767	-300	180 ft	Longer; many have tall blended winglets added
767	-400ER	201 ft	Longest 767; raked wingtips without winglets; four doors on each side
777	All		Very large engines; 6 wheels on each main gear; blade-shaped flat tail cone; no winglets
777	-200, -200ER	209 ft	Four doors on each side
777	-200LR, -300ER	209-242 ft	Longer raked wingtips and even larger engines
777	-300, -300ER	242 ft	Five doors on each side, including one directly over the wing
777	777X (-8, -9)	233-252 ft	Folding wingtips with a visible hinge line near the end of each wing; -9 is the longest twin-engine airliner
787	All		Four cockpit windows; smooth nose; long, thin wings that curve up in flight with no winglets; sawtooth engine nacelles; four doors on each side
787	-8	186 ft	10 or fewer windows between the first and second doors
787	-9	206 ft	11-15 windows between the first and second doors
787	-10	224 ft	More than 15 windows between the first and second doors

Airbus

Model	Variant	Length	How to identify
A220	All		Doesn’t look like other Airbus airliners; four cockpit windows; long, straight pointed nose; large engines for its size; canted winglets; flat tail cone
A220	-100	115 ft	About 12 windows between the front door and the overwing exit
A220	-300	127 ft	About 17 windows between the front door and the overwing exit; looks noticeably stretched
A300		177 ft	Looks like a short A330 but with a smooth belly with no bulge; three doors on each side; now mostly freighters
A310		153 ft	Shorter than the A300; two doors on each side; rare
A320 family	All		Narrow body; rounded nose; notched rear cockpit window; no triangular fin at the base of the tail
A320 family	ceo		Smaller engines; small triangular wingtip fences or curved sharklets
A320 family	neo		Larger engines that sit closer to the ground and look more open at the rear; always has sharklets
A318		103 ft	Very short; tail fin looks oversized for the fuselage; rare
A319	ceo, neo	111 ft	Short; usually one overwing exit on each side
A320	ceo, neo	123 ft	Two overwing exits on each side with no other exits between the front and rear doors
A321	ceo, neo	146 ft	Long; extra door ahead of and behind the wing (four doors on each side), or overwing exits in place of the doors on newer neos
A330	All		Two engines; notched rear cockpit window; bulge under the center of the fuselage between the wings; tall upturned winglets
A330	-200, -800neo	193 ft	Shorter
A330	-300, -900neo	209 ft	Longer
A330	neo (-800, -900)		Larger engines; longer, more curved sharklet winglets
A340	All		Four engines on a single deck; third main landing gear under the middle of the fuselage
A340	-200, -300	195-209 ft	Small engines that look undersized for the aircraft; looks like an A330 with four engines
A340	-500	223 ft	Larger engines; four doors on each side; rare
A340	-600	247 ft	Very long and slender; larger engines; five doors on each side
A350	All		Black “mask” around the cockpit windows; sleek nose; winglets that curve sharply upward
A350	-900	219 ft	4 wheels on each main gear; about 15 windows between the first and second doors
A350	-1000	243 ft	6 wheels on each main gear; over 20 windows between the first and second doors
A380		239 ft	Four engines; two full-length decks of windows; very large wings

Embraer

Model	Variant	Length	How to identify
E-Jet	All		Small, slim narrow body with engines under the wings; four cockpit windows; short triangular fin at the base of the tail; pointed tail cone
E170		98 ft	Shortest; no overwing exits; upright winglets
E175		104 ft	No overwing exits; upright winglets, or larger winglets angled at 45 degrees on newer aircraft
E190		119 ft	One overwing exit on each side; upright winglets; 11 windows ahead of the overwing exit
E195		126 ft	Like the E190 but longer, with 12 windows ahead of the overwing exit
E2	E190-E2, E195-E2	119-136 ft	No winglets; much larger engines; the E195-E2 has two overwing exits on each side

Sources

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Website Image Tags

November 1, 2026

Image tags and sizes used for link previews, favicons, and app icons. Platforms change these limits without much notice, and some are not officially documented; these were last checked in November 2026. Values marked with * are from memory or third-party sources, and other values may also rely on secondary sources.

File	Size	Used for
`preview.png`	1200x630	Large link previews on social and chat apps
`favicon.ico`	32x32	Older browsers and automated tools
`icon.svg`	Scalable	Browser tabs
`apple-touch-icon.png`	180x180	iOS home screen
`icon-192.png`	192x192	Android home screen
`icon-512.png`	512x512	Progressive web app install
`icon-maskable-512.png`	512x512	Android adaptive icons

<meta property="og:image" content="https://example.com/preview.png">
<meta property="og:image:width" content="1200">
<meta property="og:image:height" content="630">
<meta property="og:image:alt" content="Description of the image">
<meta name="twitter:card" content="summary_large_image">

<link rel="icon" href="/favicon.ico" sizes="32x32">
<link rel="icon" href="/icon.svg" type="image/svg+xml">
<link rel="apple-touch-icon" href="/apple-touch-icon.png">
<link rel="manifest" href="/manifest.webmanifest">

The icons section of manifest.webmanifest is below; web app install also needs name or short_name, start_url, and display:

{
  "icons": [
    {"src": "/icon-192.png", "type": "image/png", "sizes": "192x192"},
    {"src": "/icon-512.png", "type": "image/png", "sizes": "512x512"},
    {"src": "/icon-maskable-512.png", "type": "image/png", "sizes": "512x512", "purpose": "maskable"}
  ]
}

The 1200x630 image suits pages with a designed preview image, and fills the width of a message in chat apps. If the only image is a logo or icon, use a 280x280 square image instead so it appears as a small thumbnail next to the title, set the og:image:width and og:image:height tags to match, and use twitter:card summary. Do not reuse the 512x512 app icon for previews, since WhatsApp will show it at full size.

Use absolute https:// URLs for preview images
Use PNG or JPEG for preview images, and keep important content centered in case of cropping
Keep preview images under 600 KB, which is WhatsApp’s documented limit
Serve favicon.ico from the site root, since some tools only look there
Give the Apple touch icon an opaque background and square corners
Keep the logo in a maskable icon inside a centered circle with a radius of 40% of the icon width
sizes="32x32" reportedly stops Chrome from preferring the ICO over the SVG
Change the filename when replacing an image, since platforms and browsers cache them aggressively

Exhaustive

Link Previews

Tag	Used by	Size	Aspect ratio	File limit
`og:image`	Facebook	1200x630 (600x315 for large, 200x200 minimum)	1.91:1	8 MB
`og:image`	LinkedIn	1200x627 minimum	1.91:1	5 MB
`og:image`	WhatsApp	300 pixels wide or more for large	4:1 or narrower	600 KB
`og:image`	Discord	1200x630 in Discord’s example; no size requirement	Undocumented	Undocumented
`og:image`	Signal	Any size meeting the rules below; 1200x630 and 280x280 work	See the rules below	Undocumented
`og:image`	Slack, iMessage, others	1200x630 for large, 280x280 for thumbnail	1.91:1 for large, 1:1 for thumbnail	Undocumented
`twitter:image` (`summary_large_image`)	X/Twitter	1200x600* (300x157 minimum, 4096x4096 maximum)	2:1*	5 MB*
`twitter:image` (`summary`)	X/Twitter	400x400* (144x144 minimum*)	1:1*	5 MB*

X falls back to og:image when twitter:image is missing, but needs twitter:card to choose the card format.* X accepts JPG, PNG, WEBP, and GIF, and only uses the first frame of an animated GIF.*

Chat apps choose between a large preview and a small thumbnail using either the image’s dimensions or the page’s tags:

App	Large preview when	Source
Discord	`twitter:card` is `summary_large_image`	Documentation
WhatsApp	At least 300 pixels wide, 4:1 or narrower, and under 600 KB	Documentation
Slack	About 400 pixels wide or more	One contributor’s report, not documented
Signal Desktop	Width and height are at least 200 pixels, and not within 5% of square	Source code
Signal Android	Width is at least 150dp in device pixels, and wider than tall	Source code
Signal iOS	Width is at least about 2x the maximum message width, and height is at least 33% of that	Source code

WhatsApp documents the requirements for a large preview, and says it may relax them or revert to small previews without giving a threshold, so a thumbnail under 300 pixels wide comes from the same report. Signal does not use a single width threshold, so a large square image may still appear as a thumbnail. Discord shows a small image beside the text by default, accepts PNG, GIF, JPEG, WEBP, and AVIF, and fetches the image to measure it unless og:image:width and og:image:height are set.

Preview Image Properties

Tag	Meaning
`og:image:url`	Same as `og:image`
`og:image:secure_url`	HTTPS alternate URL
`og:image:type`	MIME type
`og:image:width`	Width in pixels
`og:image:height`	Height in pixels
`og:image:alt`	Description of the image
`twitter:image:alt`	Description of the image, 420 characters maximum*

Structured Data

Tag	Used by	Size	Aspect ratio
JSON-LD `image` on an Article	Google Search	Width x height of at least 50,000 pixels	Provide 16:9, 4:3, and 1:1
`<meta itemprop="image">`	Schema.org microdata consumers	Same as `og:image`*	1.91:1*

Favicons

Tag	Size	Used by
`<link rel="icon" type="image/svg+xml">`	Scalable	Modern browsers, including Safari 26 and later
`<link rel="icon" type="image/png">`	16x16, 32x32	Browser tabs
`<link rel="icon">` or `/favicon.ico`	16x16, 32x32, 48x48*	Older browsers and automated tools
`<link rel="icon">`	Square, above 48x48 (8x8 minimum)	Google Search results
`<link rel="shortcut icon">`	Same as `icon`	Older alternative to `icon`

App Icons

Tag	Size	Used by
`<link rel="apple-touch-icon">`	180x180	Current iPhones*
`<link rel="apple-touch-icon">`	167x167	iPad Pro*
`<link rel="apple-touch-icon">`	152x152	iPad*
`<link rel="apple-touch-icon">`	57x57, 60x60, 72x72, 76x76, 114x114, 120x120, 144x144*	Older iOS devices
`/apple-touch-icon.png`	180x180	Safari, without a `<link>` tag
Web manifest `icons`	192x192, 512x512	Android, web app install
Web manifest `icons` with `maskable`	512x512	Android adaptive icons

Legacy

These are safe to skip on new sites:

Tag	Size	Used by
`<link rel="image_src">`	Same as `og:image`*	Older scrapers*
`twitter:image:src`	Same as `twitter:image`*	Older name for `twitter:image`*
`<link rel="apple-touch-icon-precomposed">`	Same as `apple-touch-icon`*	iOS 6 and earlier
`<link rel="mask-icon">`	Scalable, single color SVG	Safari pinned tabs before Safari 12*
`<meta name="msapplication-TileImage">`	144x144*	Windows 8 tiles*
`browserconfig.xml`	70x70, 150x150, 310x150, 310x310	Windows 8.1 and 10 tiles*

Sources:

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Timezone Boundaries Mapped

September 25, 2026

The IANA timezone database contains over 400 timezone entries mostly named as “<continent>/<city>”. They are meticulously cataloged to group regions of the world not only by UTC offset but also by the presence and timing of Daylight Savings as well as current and historical timezone policy changes.

The github.com/albertyw/localtimezone repository maps latitude/longitude data to IANA timezone names. It is based on github.com/evansiroky/timezone-boundary-builder which in term is based on OpenStreetMap. From that data, I generated an Interactive Map:

Timezone Map

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Comparing WebdriverIO Firefox vs Chrome

September 5, 2026

Chrome recently started releasing arm64 linux builds which meant that my ubuntu-on-m1-mac can run webdriverio (wdio) builds on both firefox and chrome (it was previously stuck doing only firefox builds).

I therefore compared build speed of codemancer on firefox versus chrome.

wdio.conf.ts Configuration

Firefox:

capabilities: [{
  maxInstances: 5,
  browserName: 'firefox',
  'moz:firefoxOptions': {
    args: ['-headless'],
  },
  acceptInsecureCerts: true,
}],

Chrome:

capabilities: [{
  maxInstances: 5,
  browserName: 'chrome',
  'goog:chromeOptions': {
    args: ['--headless=new', '--no-sandbox', '--disable-dev-shm-usage', '--disable-gpu'],
  },
  acceptInsecureCerts: true,
}],

For Arm architectures, the most recent version of wdio still depends on @puppeteer/browsers at ^2.2.0 which doesn’t correctly fetch Chrome’s Arm builds. Therefore, these additional configs need to be added to wdio.conf.ts:

// Set these environment variables to manually-downloaded chrome executables
// For the satantime/puppeteer-node:26-trixie-slim docker images, use
// CHROME_BINARY=/usr/bin/chromium
// CHROMEDRIVER_BINARY=/usr/bin/chromedriver
const chromeBinary = process.env.CHROME_BINARY;
const chromedriverBinary = process.env.CHROMEDRIVER_BINARY;

// inside capabilities
'goog:chromeOptions': {
  args: [/* ... */],
  ...(chromeBinary ? { binary: chromeBinary } : {}),
},
...(chromedriverBinary ? { 'wdio:chromedriverOptions': { binary: chromedriverBinary } } : {}),

Benchmarks

I benchmarked both browsers on codemancer unit tests over 30 iterations.

On Arm64, Chromium 151 against Firefox 155:

browser    runs      min   median     mean      max
chrome       10   4934ms   6593ms   7143ms   10054ms
firefox      10   7055ms  11426ms  17360ms   50600ms

On x86_64, Chromium 152 against Firefox ESR 140:

browser    runs      min   median     mean      max
chrome       10   4433ms   5265ms   6798ms   15222ms
firefox      10   6645ms   9119ms  18613ms   56509ms

References

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Geolocation Precision

July 4, 2026

Latitude/longitude and other geolocation systems can express a position at exponentially increasing precision as you add digits or levels. Below are tables of the approximate ground precision of several coordinate systems.

One degree of latitude is roughly constant everywhere (~111 km), but one degree of longitude shrinks toward the poles as the meridians converge, scaling with the cosine of the latitude. For the latitude/longitude systems below, the east/west distance is therefore given at several latitudes. Grid systems like H3, S2, Geohash, and Plus Codes are designed to be nearly uniform across the globe, so their precision is instead given as an approximate cell edge length and area.

Degrees with decimals (Degrees)

Degrees	Decimals	E/W at equator	E/W at 20° N/S	E/W at 45° N/S	E/W at 70° N/S
1	0	111.3 km	104.6 km	78.72 km	38.07 km
0.1	1	11.13 km	10.46 km	7.872 km	3.807 km
0.01	2	1.113 km	1.046 km	787.2 m	380.7 m
0.001	3	111.3 m	104.6 m	78.72 m	38.07 m
0.0001	4	11.13 m	10.46 m	7.872 m	3.807 m
0.00001	5	1.113 m	1.046 m	78.7 cm	38.1 cm

Degrees-minutes-seconds (DMS)

Precision	Unit	E/W at equator	E/W at 20° N/S	E/W at 45° N/S	E/W at 70° N/S
1°00′00″	degree	111.3 km	104.6 km	78.72 km	38.07 km
0°01′00″	arcminute	1.855 km	1.743 km	1.312 km	634.6 m
0°00′01″	arcsecond	30.92 m	29.06 m	21.87 m	10.58 m
0°00′00.1″	0.1 arcsecond	3.092 m	2.906 m	2.187 m	1.058 m
0°00′00.01″	0.01 arcsecond	30.9 cm	29.1 cm	21.9 cm	10.6 cm

Geohash (base32)

Each geohash character adds 5 bits, alternating between longitude and latitude, so cells are square at odd lengths and 2:1 (wider than tall) at even lengths.

Length	Cell size (lng × lat)	Ground size at equator
1	45° × 45°	5,009 km × 5,009 km
2	11.25° × 5.625°	1,252 km × 626.2 km
3	1.406° × 1.406°	156.5 km × 156.5 km
4	0.3516° × 0.1758°	39.14 km × 19.57 km
5	0.04395° × 0.04395°	4.892 km × 4.892 km
6	0.01099° × 0.005493°	1.223 km × 611.5 m
7	0.001373° × 0.001373°	152.9 m × 152.9 m
8	0.0003433° × 0.0001717°	38.22 m × 19.11 m
9	0.00004292° × 0.00004292°	4.777 m × 4.777 m

Plus Codes (Open Location Code)

Code length	Cell size	Ground size at equator
2	20°	2,226 km
4	1°	111.3 km
6	0.05°	5.566 km
8	0.0025°	278.3 m
10	0.000125°	13.92 m
11	0.000025°	2.783 m
12	0.000005°	55.7 cm

H3 hexagonal geospatial indexing

Resolution	Avg edge length	Avg cell area
0	1,281 km	4,357,449 km²
1	483 km	609,788 km²
2	183 km	86,802 km²
3	68.98 km	12,393 km²
4	26.07 km	1,770 km²
5	9.854 km	253 km²
6	3.725 km	36.13 km²
7	1.406 km	5.161 km²
8	531.4 m	0.7373 km²
9	200.8 m	0.1053 km²
10	75.86 m	0.01505 km²
11	28.66 m	2,150 m²
12	10.83 m	307 m²
13	4.092 m	43.9 m²
14	1.546 m	6.27 m²
15	58.4 cm	0.895 m²

S2

Level	Avg edge length	Avg cell area
0	7,842 km	85,011,012 km²
4	490 km	332,074 km²
8	30.63 km	1,297 km²
10	7.658 km	81.07 km²
12	1.915 km	5.067 km²
16	119.7 m	0.0198 km²
20	7.479 m	77.3 m²
24	46.7 cm	0.302 m²
28	2.92 cm	11.8 cm²
30	7.3 mm	0.737 cm²

UTM (Universal Transverse Mercator)

UTM projects each of 60 longitudinal zones (each 6° wide) onto a flat grid and expresses a position as an easting/northing in meters within the zone. Because the coordinate is already metric, the precision is simply how many digits of the easting/northing you keep.

Easting/northing digits	Rounded to	Ground precision
550__	10 km	10 km
5502_	1 km	1 km
55020	100 m	100 m
550200	10 m	10 m
5502001	1 m	1 m
5502001.0	0.1 m	10 cm

MGRS (Military Grid Reference System)

MGRS is a grid-based alphanumeric encoding built on UTM (and UPS at the poles): a grid-zone designator, a 100 km square identifier, then equal numbers of easting and northing digits. Each added digit pair narrows the cell tenfold.

Digits (per axis)	Example	Ground precision
0	10SEG	100 km
1	10SEG12	10 km
2	10SEG1234	1 km
3	10SEG123456	100 m
4	10SEG12345678	10 m
5	10SEG1234567890	1 m

Maidenhead locator system

Used by amateur-radio operators, Maidenhead alternates letter and number pairs (field → square → subsquare → …) to encode longitude and latitude. Cells are 2:1, wider than tall, because longitude spans 360° against latitude’s 180°.

Characters	Cell size (lng × lat)	Ground size at equator
2 (field)	20° × 10°	2,226 km × 1,113 km
4 (square)	2° × 1°	223 km × 111 km
6 (subsquare)	5′ × 2.5′	9.277 km × 4.638 km
8 (extended)	30″ × 15″	927.7 m × 463.8 m
10	1.25″ × 0.625″	38.65 m × 19.33 m

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Notes

Airliner Identification

Quick Key

Airbus vs Boeing

Boeing

Airbus

Embraer

Sources

Website Image Tags

Recommended

Exhaustive

Link Previews

Preview Image Properties

Structured Data

Favicons

App Icons

Legacy

Timezone Boundaries Mapped

Comparing WebdriverIO Firefox vs Chrome

wdio.conf.ts Configuration

Benchmarks

References

Geolocation Precision

Degrees with decimals (Degrees)

Degrees-minutes-seconds (DMS)

Geohash (base32)

Plus Codes (Open Location Code)

H3 hexagonal geospatial indexing

UTM (Universal Transverse Mercator)

MGRS (Military Grid Reference System)

Maidenhead locator system