Not going to get into the functions but basically, been surronded by infps my entire life and here are some stark differences without functions. Some can differ obviously, this is just my two cents, not all this is going to be butterflies.

I see things in colours sometimes. INFP is purple whereas infj is black or white.

INFP will usually have a wider circle of friends who they feel they're deeply connected with in a unique way. Most people will view infp as being approachable, trusting (often infp will trust everyone to a degree until proven wrong- often has a lengthy history of feeling hurt by others deceiving them), positive, strong morals, fun, deep, loyal (naively so often) and unpredictable. Friends gravitate towards the infp in order to talk about the world, to experiment especially gravitating towards substance abuse when younger, and see different angles. INFP will often feel others 'open up to them' but others will find the INFP has a bad habit of turning conversation inwards about them. This is the use of the fi to relate their experiences to their friends. Not intended to be selfish. INFP enjoy dreaming about travelling to distant and exotic places, they day dream about fantasy (often their daydreams are not based on real world), and often care a great deal about being loved. Their hidden agenda is to be loved and have someone love them for who they are. INFP enjoy taking care of others, exploring themselves, often are musically inclined, artistic inclined, or have some sort of niche but whatever it is, they dig incredibly deep into. This, for them, is self expression of their inner world. INFP surrrond themselves often with symbols, moreso than the average person. Their rooms/caves are often filled with past memorabilia as the INFP will struggle throughout their life living in their past. The past for the INFP is a hyper sensitiveness topic which they often find can be overwhelming, especially when past events are recent. INFPs are prone to depression and hopelessness. The fi leading function in younger INFPs often can cause disillusionment with a common theme of bullying. INFPs if not self aware, will find themselves with a strong victim complex as they are out of touch with others and flex their feelings as superior. They can live in this victim complex for years despite others trying to pull them out. INFPs make excellent partners, especially sexually. INFPs tend to be sexually liberated and view sex as both a recreational activity or if feelings are involved, as loving. INFPs are loyal to almost everyone they know until proven wrong- especially partners. Ted Mosby is your classic INFP, always searching for the one despite telling others at times, he is not interested. INFP strongly value love. However, INFPs once a relationship is over, tend to fall completely out of love and take an extraordinarily long time to get over things. In relationships once matured, they're often stable, considerate, thoughtful, and loyal. When immature, in relationships they can be suffocating, overbearing, overemotional, blameful, condescending, and toxic. In general, often requires reassurance from their partners and to be told often they are loved. They're intelligent, creative, emotionally intelligent. INFPs will be seen as others as being selfish and moody but these are just minor bad traits everyone has. Physically often has troubles picking what general population would consider a typical wardrobe but has own style. Enjoys and often wears, bright colours or interesting patterns. Bright coloured hair, piercings and tattoos are common.

INFJs will usually have a handful of true friends they keep for a lifetime. They often feel disconnected from others. Most people will view infj as being distant, mysterious (infj tends to have the mindset of earning trust), neutral, deep and feel uncomfortable at times (this is due to inability of others to know what INFJ is thinking and INFJ not telling others). Friends gravitate towards the INFJ in order to talk about the universe, their problems, or needed perspective. INFJ will often feel others 'open up to them' but rarely genuinely cares about them. Overtime this is one of the reasons INFJs grow distant. Their fe can make them servants of others. INFJ enjoy dreaming about helping the world and feel guilty about secretly wanting credit. INFJ do not place high emphasis on being loved but once in love, tends to stay in love to a degree unlike INFP. INFJ takes relationships seriously and looks for a life partner rather than a fling. Once over, INFJ recognizes the conclusion and moves on quickly. Their hidden agenda is to be healthy, contribute, and know why. INFJ enjoy taking care of others but moreso someone they do not know at all or someone they deeply love, understanding themselves and improving. INFJ tend to have areas of interests which they dig into rather than an outlet. Outlets are usually private or channeled through their curiosity (hidden agenda: "why"?) INFJ may surround themselves with symbols but often feels disconnected from physical world and won't be very materalistic or nostalgic. Their rooms are often filled with memorabilia serving the purpose of reminding them where they want to go. The past for the INFJ is often very foggy which they often find irrelevant or frightening at times when asked to remember details or an event. INFJ have incredibly strong memories if it involves emotions but again, must realize it's subjective. Often does not care about the past but moreso, the future. INFJ are prone to anxiety and overstimulation (ni + fe). INFJs if not self aware, will find themselves disregarding others ideas of them, ideas of others, and develop a superiority complex. The fe often helps the INFJ quickly identify and correct mistakes- especially that of other people. INFJs make excellent partners, especially sexually. INFJs tend to be sexually conservative when not committed and view sex as spiritual and a sign of their love. Often want to serve their partners and have little boundaries when feeling safe and committed. INFJs are loyal to only chosen few and often trusts their loved ones too much, causing one sidedness. INFJs when in love, can be exceptionally naive and go into strong denial of partners wrongdoing. Highly likely to be emotionally manipulated, likely to be cheated on, likely to take over responsibility (marytr complex) and likely to doorclose (not slam) their past partners. In relationships once matured, they're often stable, considerate, thoughtful, and deeply loyal. In relationships when immature, often over enthusiastic, high expectations, servant like when unwanted (think puppy), long term thinkers, and wishy washy about committing. Younger INFJs tend to have commitment problems and will abandon potential partners very quickly if they feel they don't have the solid connection to sustaining their relationship- needs a stupid amount of distance. Overall romantically very straightforward. They often need authentic communication which lets them know their partner cares. They're intelligent, curious, and playful. INFJs will be seen as others as being too serious, distant, cold, closed off, stand offish, and confusing but these are just minor bad traits everyone has. Physically often slender (hidden agenda, health), classic style, usually layered clothing, muted colours with pops of brightness (gray, black, white), hair is often natural or a natural colour, natural style, tends to stay away from piercings or tattoos unless deeply meaningful to them.