As the Sumerian and Egyptian early dynasties share common origins, the writing system initially looked rather similar:

Kish tablet 3500 BC

The development of scripts is closely linked with the "secondary products" revolution: wool, clothing, metals, honey, bread, oil, beer, textiles, garments, rope, mats, carpets, furniture, jewelry, tools, perfume—all of these things and many more needed to be accounted for. The number of types of tokens in use ballooned to 250 by 3300 BCE and over a thousand after 3000 BCE, followed by a reform in which many complicated signs where abandoned.

Most alphabets of the world are derived from the Egyptian syllable-extended alphabet and/or the pure Ugaritic alphabet of 1400BC. The brilliance of the Egyptian alphabet is that they uses common Sumerian signs and applied them in a free standing, non determinant way.

Akkadian Greek Coptic Gothic alphabets show similar traces of silent components.

The earliest attested ordering of signs are Halaham and Abjads. We follow Gardingers and Schneiders view that these likely have deep origins in at least the Middle Kingdom if not early Pharaonic times.

We mostly follow the conventional reading of the signs, with the exception of letter 'f' pth 𓆑 vs 𓇋e.

𓂝 𓃀 𓍿 𓏏 𓂧 𓇋 𓇋 𓎼 𓉔 𓇋 𓆳 𓎡 𓐍 𓏯 𓅓 𓈖 𓏲 𓊪 𓏘 𓂋 𓍯 𓋴 𓏏 𓅱 𓅳 𓏴 𓏭 𓊃 + 𓄿 𓎛 𓈙

The following are the most frequent signs of the hieroglyphics ordered by the modern roman alphabet. For the complete sign list see Gardinger signs. You can search and enter those signs with the online Dictionary/Keyboard

letter	gard	sign	comment
A	𓂝	Arm	á 𒀉 PIE √h₂erm haraṇa (hand) A&O𓂣דראע𐤂 अस aṃs dharma etc
a	𓄿	Aar	Air al'pha𓃾 earn=eagle
b	𓃀	Bein	پَا 𒉽𒄬pap-half/pa-demi/ƥođ/ƥleɠ𓂾jambone𓄹𓄻 𓋁 𒁇bar/par 𒈦ban
c	𓍿	Ceh Z𓊃S𓋴	ⵛappa𓏘𓎡𓍿 TS/ST ⵛ toe Tau? 𒄑
D	𓏏	Delle/Tell	𓏏𓏏dad=tit 𓂧δeirm𓂝 𒆕DU=do,build
D	𓂧	Daum	Ⲇ/δr/cheir/χειρo 𓄛 dast@Pers 𒋰dab double
E	𓇋	fEather 𓏭	fEδer leicht (V)ι,e,i,a,ey ו ee↔i
F	𓇋	Fieder𓆑	𓇏fen 𓇌Viper phython=PhSn=:ϝn φϑظ
G	𓎼	Ɠiebel𓏘	Kübel piK γ,κ,Γ,g,χ 𓌨𓊖𒆸Gur 𒂷ĝa Korb
H	𓉔	HOuse	Hair𓎛𓍢𓏲 Hundreh𓅱𓏲=100 hE𒂍
Ḫ	𓎛	Ḫelix
I	𓇋	fIeder	𓏤 (V)ι,e,a,ey,𓇌,ee=i,y
J	𓆳	𓇋𓇋	Jahr𓇺year 𓆓dj Ja?𓆶𓆴 Jana
K	𓎡	Kelle	𓆼 kilo k-l-l=𓎟 𓎡𓎡𓇰
Kr	𓐍	Kreis	gray𓊖kur/gyr𓌨*kar𓂓
L	𓏯	Leo𓃭	𓈖𓇋𓇋𓌴 yλ niL 𓂅𓍢 𓂢Elle 𓌳ל¬laMed 𓂋 𓋴𓆓𓄓 𓄿lark
M	𓅓	Musen𒈪	𓏇𓇋𓅱𓃠mµnνuvw𐀖 Mut:𓂋𓅱𓅐𓀁 𓈗𓏠
N	𓈖	NiL𓌳	NAUtik 𓈖𓏤=𒈾 NAr.mer 𓈗mnuwave μν
O	𓍯	όριο	rho ϱ 𓍯rogue 𓂣A&O𓂝 o < p𓊪/k口/m𓂋/r𓂋/w𓊪/wh𓏲/h𓉔
Po	𓊪	pad𐦈/pool	who𓊪𓏲 𒉺𐠞匹pǐ πⲠב𐀡𐠡Ⳁϱρрro pan ἀπο
Q	𓏘	Quarꜩ	𓈎𓏇𓇋𓇋 Gummi 𓌽𓂋Gersten Korn 𓎡⋍q 𓎼𓐎𓁷𐀣
R	𓂋	eaR	ohR àr arse ϱρрrot=Mund@Rus 𓏲round roài® 𓂌 𓂍 reciproke rayns الفم
R	𓍢𓏲ϱ	𓍯𓍢𓏲	rogue rhound⋍100
S	𓋴	𓏏𓆓	S'S C'S ß Γ ʃ δ 𓏏 Ⲋ𓆓 Shad𓈙Sea
T	𓏏	Teig	Dough 𓏏𓏏TiT tick𓏴tag𓏵Tag 𓏏th⋍s 𓍔 𓍘 𓄜𓄛
U	𓅱	𓍢𓏲	HUhndert=100 𓏌Ων ωuν 𓏲𓍢وقف𐀸 wound
V	𓇋	viehder𓇋𓇋vaw	vyλ 𓅡phauw ννν:fun 𓄲 𓇋𓇋 va𓇋
W	𓅳	uu𓏲𓍢	ων waw 𓍢rwound 𐀸 𓎛wHr wΩm -mos µhwn𓅱 𓅓µwū乌 𓍢𓏲ϱr
X	𓏴	𓏵	𐄂χX 𐠷=CS 𓎡𓋴 𓍲𓏴 ticks✓ 𓂧[end] Ξξ
Y	𓏭	¨𓏮 𓇌 𓇋𓇋 𓆄𓆄	vyλ丫yā:fork yuvw T+𓏮=TWO亚 义羽Yǔstice 𐀂Y 𓎡yek/juɠ
Z	𓊃	Zone	zusam syn 𓍿,ʒ,Z,Σ,ß,ss,ts,c,δ 𓄑
Sh	𓈙	sea sluice 𓈙𓈇 شط Shatt
Sh	𓈉	Schanze	山ШшЩщ 𓆷swampϢ ∑ 三 sān Karδan 𓂓𓈋𓈙

This list is obviously a modern arrangement, what constitues a letter in the Egyptian Alphabet was not as clear cut: Many signs for prefixes, infixes, and suffixes had phonetic values. Determinants could appear in different places with often unknown influence on the phonetics of the word.

Signs which appear in different positions, or are used clearly phonetically: 𓌴 𓌳 𓍱 𓇥 𓌨 𓅮 𓅯 𓐠 𓆼 𓏌 𓁶 𓁷 𓂾 𓆄 𓐝 𓐛 𓐙 𓈅 𓇉 𓍑 𓐟 𓄡 𓅠! 𓏶 𓁹 𓌕 𓏇 𓐪 𓂞 𓌗 𓇿 𓄫 𓇑 𓍇 𓌰 𓈟 𓆷 𓍔 𓍘 𓍃 𓉻 𓂸 𓆰 𓌈 𓄖 𓂓 𓌘 𓌟 𓇐

Few of these would be counted towards an alphabet proper. Arguably only 𓌳 𓐝 … ?

Special: 𓈇 𓏤 𓏮 𓏥 𓏛 …

Many signs appear only or mostly in clusters (reminiscent of x ≈ ks, german "pf" "sch" … ) : 𓃀 𓅡 𓈖 𓅘 𓈖 𓌰 𓅓 𓌢 𓈖 𓃹 𓈖 𓄚 𓈖 𓏠 𓈖 𓇋 𓆛 𓈖 𓊃 𓆛 𓈖 𓎛 𓆰 𓈖 𓏅 𓈖 𓏏 𓅨 𓂋 𓇥 𓂋 𓈖 𓄓 𓎡 𓊃 𓅭 ( but many other contexts!) 𓆎 𓅓 ( but abbreviated as 𓆎 𓏛, 𓆎 𓏏 𓏌 𓏤, 𓆎 𓏏 𓊖)

Only prefix / suffix ( but with vastly different semantics ) : 𓐎 𓐡

Rare infixes can hint at etymological word boundaries:
𓈖 𓆱 𓐍 𓏏 𓂡 | victory| nike.toir @ greek

see π forms

The coherence of signs, meaning and 'cognate' sounds is striking, but if nothing else these are excelent mnemonics.

Each and every letter of this alphabet had an enormous influence on neighbouring countries and cultures.
In fact around the time of the Bronze Age collapse ⋍1200BC the convergence with Akkadian and Ugaritic cuneiform becomes noticeable, especially Ugaritic looks almost like the Phoenician alphabet put into stone.

Even in its early form, the Egyptian hieroglyphics system was 'almost alphabetic'. A quite small and easy to learn system of syllables, at least compared to Chinese.
The exact phonetic values are impossible to reconstruct, but comparative linguistics can give estimates for the dominant dialects. Even at the time when this language was still spoken most letters were clusters of similar sounds (see different values of 'a' in 'man','made','master',…)
For example many Egyptian words which have the character '𓃀' now have a 'b' in its derived coptic forms, or similar bh,ph,p,v,f sounds in modern variants of the word '𓃀' (all meaning ⋍leg)

Likewise 𓏏 blurred into a spectrum from D, DT, DH, T, TH, S

There is a huge cluster of hundreds of derive related words in many languages (pedestrian,𐀴 𐀪 𐀷 𐀆 (ti-ri-po-de = tripod Linear A), …,)

Dr. Christian De Vartavan did fantastic work reconstructing the pronunciation of the late stage of Egyptian. We take a somewhat different approach and try to reconstruct the early/middle forms of the signs when they were optionally readable as Complete Words, before they were reduced to syllables and phonemes.
It is admitted and obvious that the consensus mechanism went a bit too far: many words in dictionaries are reduced to the common denominator and just sequences of vowels a-a-a, etc. Thus while it is custom to treat determinants as silent signs, we treat them mostly as voiced infixes / suffixes.

A modern pendant would be:
New York 𓊖𓏏𓏤
New York City

In some cases both approaches seem legitimate, in others it seems more natural to include the suffix:

• 𓍋𓃀𓏲𓄛𓏪 L'Banther
• 𓍋𓃀𓅱𓃰 El'Phan(ter)
• 𓍋𓃀𓏲𓃮 El Panther

Through contract with demotic priests, medieval Arabian scholars Al-Idrisi (Anwar: 100f) and Al-Qalqashandi (Subh 3: 20) knew that the ancient Egyptians, whom they call al-qibt al-awal, had 32 to 36 letters in their alphabet. They both referred also to the fact that Coptic was linked to the ancient Egyptian language by calling the latter al-qibitiyah al-ula (the First Coptic). Source: ancient-egypt-in-medieval-arabic-writings

Signs which appear outside their deterministic context and are thus used as letters or syllables are listed in the extended alphabet.

The use of the Egyptian extended alphabet surely led to shifts in the spoken languages via phenomena such as https://en.m.wikipedia.org/wiki/Spelling_pronunciation

Recent research shows that knowledge of the Egyptian alphabet and its phonetic values was never completely lost and European scholars in the 19ths century might have drawn on Arabian sources:

See Subtleties for series of ever so slightly different signs.

Wadi el-Hol / Sinatic Alphabet and Byblos Syllabary