As stated this will contain the changes that has been made or added in to extent the story line for that episode. There are a ton of episodes so there maybe a second part to this thread, I will update this part if there was split for this.
Update: There is missing information or little known information for the change that has made to the anime counterpart as the information from the site I had the information hadn't have it and missing information may not fill as it hasn't be update like forever through I still will put as to be updated. There is also a couple of remake that I will include at the end of the episode that I had stopped at. Also this list not only contains the normal episode changes it will also have trivia, the list will be following it date of airing.
Update 2: OVA 2 has two different date but I put the first releasing instead of the second date, also Movie Episode Chopper has two version but the 2014 version will be posted as a separate post through there was only one newly added scene. Due to the total or current numbers this post will be extremely long but I will stop here on 18/04. I will get back to post the changes on Saturday the earliest or Monday the latest, as I will be away.
Update 3: The 12th movie was shown in between the fillers that was running at that time and the Phone Smart Short too all of them running very close to each other, as I had stated before this list will try to follow the airing order as close as possible so this is the reason why the episode did not run in order it was this reason.
Update 4: Some of the Bulletin and Numbering maybe wrongly label but I tried my best to make sure that it is right.
Episode 786 - Totto Land! Emperor Big Mom Appears!
The anime adds the following:
More scenes of Luffy and Chopper exploring Chocolat Town.
After Pekoms explains about Chocolat Town, Brook asks if there are panties made of chocolate.
At Pudding's house, Brook is going to ask to see Pudding's panties until Nami interrupts him.
Before having the conversation with Pudding, the anime adds scenes of Luffy and Chopper eating the walls of Pudding's house.
Additional scenes of Amande, Diesel, and Randolph, which also shows off their designs before they were unshadowed in the manga.
Unlike in the manga, when Carrot sees the inhabitants of Cacao Island from the Thousand Sunny, she has to use binoculars.
The doomed inhabitants of the islands where Big Mom's subordinates gather ingredients for the wedding cake know about Big Mom's objective for a Tea Party.
Episode 785 - A Deadly Poison Crisis! Luffy and Reiju!
The anime adds the following:
While Yonji was hovering in the air, Chopper and Nami wonder if it was a Devil Fruit power or some special skill.
After Pekoms explains about Germa 66's technology, Chopper becomes fascinated.
After the Sanji Retrieval Team part ways with Reiju and Yonji, Chopper examines Luffy's condition.
Before reaching Cacao Island, the Thousand Sunny encounters a tarte and the Sanji Retrieval Team hides in the cabin.
In the manga, Reiju thanked the Straw Hats for taking care of Sanji before explaining about her father's search for him. In the anime, it is after.
In the manga, Pekoms explains about Totto Land after the Sanji Retrieval Team arrived at Cacao Island. In the anime, it is before.
When the anime shows Cacao Island, the town appears to be further from the coast than in the manga.
Episode 784 - Zero and Four! Encountering Germa 66!
The anime adds the following:
Right after Chopper warns the group about the fish's poisonous skin, Luffy insists that he was alright.
Nami cooking the fish is shown.
When first encountering Reiju and Yonji's Germa ship, the Sanji Retrieval Team briefly hid themselves.
In the manga, Luffy only pulled the giant fish out of the water only once. In the anime, the fish jumped back into the water and nearly pulled Luffy off the ship. After a brief struggle, Luffy catches the fish with Chopper, Brook, and Pedro's assistance.
While Luffy is suffering from food poisoning, he is not foaming at the mouth like in the manga.
Whole Cake Island Arc
Episode 783 - Sanji's Homecoming! Into Big Mom's Territory!
The opening, "We Can!", now shows future scenes from the Whole Cake Island Arc.
The anime adds the following:
The Sanji Retrieval Team going through a storm while starving.
After showing Sanji the picture of Pudding, Vito asks him what he thinks about his fiancee.
As Chiffon is dragging Gotti out of Sanji's room, Sanji tries to talk to her and Chiffon apologizes for Gotti's behavior. In the manga, Sanji and Chiffon were not shown interacting with each other during that time.
After Vito leaves Sanji alone in his room, Caesar cries in terror at the thought of being killed by Big Mom while also complaining that Sanji is receiving better treatment.
Reiju and Yonji make an earlier debut in the anime though their appearances are shadowed. In the manga, they first appeared when the Sanji Retrieval Team encountered them after Luffy got food poisoning.
The anime shows more illustrations of the comic strip, "Sora, Warrior of the Sea" than in the manga. In the manga, only Sora's back was shown.
Illustrations of all the Germa 66 commanders are also shown. In the manga, only Judge, Ichiji, and Niji are clearly shown.
The scene of Luffy catching the giant fish is extended.
This is the first episode of the Whole Cake Island Arc.
Episode 782 - The Devil's Fist! A Show Down! Luffy vs. Grount!
Luffy defeats Vice Admiral Prodi.
A flashback reveals how Grount first met Kuzan.
Luffy defeats Bonham and Zappa.
Grount unleashes the power of his left arm.
Grount and Luffy have their third fight with Luffy ultimately becoming the victor.
Luffy and his group leave the Fron Island Marine base with the food, but they quickly ate all of it.
Episode 781 - The Implacable Three! A Big Chase After the Straw Hats!
Luffy and his group battle Grount, Bonham, and Zappa.
Bonham is revealed to have Rokushiki during his battle with Luffy.
He only has shown Shigan, Rankyaku, Soru, and Tekkai.
After overpowering Grount, Bonham, and Zappa, Luffy and his group are confronted by Prodi.
Marine Rookie Arc
Episode 780 - A Hungry Front! Luffy and the Navy Rookies!
The Sanji Retrieval Team goes to an island that Nami saw on a sea chart back in Episode 775.
Marine Captain Grount is stationed on Fron Island under Vice Admiral Prodi.
Grount seeks to take down Big Mom.
Grount and his comrades Bonam and Zappa used to serve under Aokiji.
Luffy, Nami, Carrot, Chopper, and Brook infiltrate the Marine base stationed on the island while Pedro and Pekoms watch over the Thousand Sunny.
Garp and Koby make their first post-timeskip appearance in the anime series. Prodi is close to Garp.
The Marines discover the Straw Hat Crew and Grount prepares to fight Luffy.
Episode 779 - Kaido Returns! An Imminent Threat to the Worst Generation!
The anime adds the following:
While preparing the meal, Luffy poorly cuts the ingredients.
Chopper tending to Pekoms' injuries right before Pedro reveals the news about the Revolutionary Army's base.
The anime shows Chopper's reaction right after hearing about Sabo's relationship to Luffy.
Carrot and Bariete's conversation before Carrot left Zou is shown.
The anime extends the following:
The scene where the Sanji Retrieval Team encounters a storm.
Wanda and Bariete's conversation with Bariete trying to deny that he was bribed by Carrot.
The scene where Kaido is grieving over his loss of SMILEs.
There is an animation mistake where the newspaper showed a happy Sabo photo but in another scene, he appeared serious in the picture.
This is the last episode of the Zou Arc.
Episode 778 - To the Reverie! Rebecca and the Sakura Kingdom!
The anime adds the following:
After Carrot shows the provision she brought along, Brook comments on the shirt with a carrot on it.
After Nami says she'll charge the crew for preparing food, Chopper and Brook take some time to think who should cook before Luffy volunteers to do it himself. Brook and Chopper are also shown trying to stop Luffy.
The anime shows dwarves and the children of Dressrosa wearing Straw Hats.
After Viola invites Rebecca to the Levely, Rebecca checks which gown to wear before deciding to wear her mother's dress.
Brook giving Carrot a tour of the Thousand Sunny.
This episode gives a recap on Chopper's past and the Drum Island Arc.
Dalton, Kureha, and Wapol make their first post-timeskip anime appearance.
When Wapol is reintroduced, he narrates the events of Wapol's Omnivorous Hurrah.
Wapol does not mention that the World Nobles granted him his new kingdom as a reward for his successful business.
Miss Universe and Hakowan appear for the first time in the anime.
The locations of Drum Island, the Black Drum Kingdom, and Dressrosa are shown on the globe.
Episode 777 - To the Reverie! Princess Vivi and Princess Shirahoshi!
The anime extends on Vivi's departure from Alabasta.
Vivi remembers her friendship mark and wonders if she will see the Straw Hats again.
This episode gives a recap on the Alabasta Arc.
The anime shows more of the hotel room that Sterry and his wife are staying at.
The anime combined the two last panels before introducing the Kano Country king, into one Levely participant.
Koza, Toto, Cobra, Pell, and Igaram make their first post-timeskip anime appearance.
When Cobra is thinking about Robin, the flashback of her saying about having too many enemies is omitted.
Episode 776 - Saying Goodbye and Descending from the Elephant! Setting Out to Take Back Sanji!
The anime adds the following:
Kin'emon showing his Vivre Card right before reviewing the objectives of each of the four groups.
Before Pedro volunteers to join Luffy's group, Nekomamushi tells his Guardians to protect Zunisha in his absence.
After Pedro calls Sicilian noisy, Sicilian begins charging at Pedro until Wanda comes between them.
Right after Nami extends her new clima-tact, she spins it uncontrollably for a brief moment.
As the Sanji Retrieval Team departs Zou, the anime adds Brook receiving a farewell from the dog minks while Chopper receives a farewell from Tristan, Miyagi, and Milky.
When Luffy is searching for Pekoms, the anime shows Luffy standing on top of Pekoms before discovering him.
The anime shows more minks volunteering for the Sanji retrieval mission.
Vivi, Karoo, and Chaka make their first post-timeskip anime appearance.
Episode 775 - Save Zunesha! The Straw Hat's Rescue Operation!
The Straw Hats and the Mink Tribe's efforts to treat Zunisha's wound is expanded upon in the anime and additional scenes are added.
A flying squirrel mink named Musatobi checking on Zunisha's leg wound.
Chopper helping with gathering medicinal herbs and Robin helping with making bandages.
Franky asking Inuarashi about the minks' possession of ships and Sicilian showing him how they would deploy them.
Nami asking Wanda for a sea chart to Whole Cake Island and Pedro later showing an old one to her.
Brook, Kin'emon, and Zoro cutting down trees for wood.
Franky repairing the ships that were damaged during Jack's attack.
The Straw Hats and the minks encountering a complication in the form of a storm.
Carrot taking Luffy to the food storehouse where he collects food for the upcoming journey to Whole Cake Island.
In that scene, Carrot asks Luffy if she could join him, but Luffy does not hear her question as he suddenly remembers Pekoms and went off to find him.
Carrot deciding to go out to sea and giving Bariete some bananas are shown onscreen while they happened off-panel in the manga.
Episode 774 - A Battle to Defend Zou! Luffy and Zunesha!
The anime adds the following:
Franky saving Tristan from a collapsing house.
Zoro and Raizo saving the minks from a falling tree.
Usopp pointing out that Jack is a Devil Fruit user and is relieved when Nekomamushi states that Jack must have died when he fell into the water.
The anime shows Zunisha swinging its trunk twice, the first to send Jack's fleet into the air and the second to smash the ships.
Episode 773 - The Nightmare Returns! The Invincible Jack's Fierce Attack!
The following scenes are extended:
Luffy trying to remember Marco is extended with Usopp, Franky, Brook, and Chopper also helping.
Extra dialogue is added to the scene where the Straw Hats, Law, Inuarashi, Nekomamushi, and the samurai are planning their next move.
Raizo using his Daisuki no Jutsu.
The anime adds the following:
Before Zou started shaking, Zoro, Inuarashi, and Nekomamushi sense imminent danger.
While Zou is under attack, Carrot tells Usopp what Zunisha is.
Law saving his crew from a collapsing building while Franky and Robin are also shown helping some minks during the chaos.
Episode 772 - The Legendary Journey! The Dog and the Cat and the Pirate King!
The anime adds the following:
When Luffy says Pekom's nickname to Inuarashi, Nekomamushi laughs at it.
After Jack reminds Sheepshead on his failure to find Raizo, Sheepshead apologizes.
Ginrummy showing surprise when Jack states his intent to kill Zunisha.
When Jack and his men return to Zou, the episode only shows three ships. The manga showed more ships than that.
Episode 771 - A Vow Between Two Men! Luffy and Kozuki Momonosuke!
After Luffy's group learns that Oden was part of Roger's crew, we're then given a recap on the Void Century.
The anime adds the following:
Usopp asking the samurai if they knew the secret of the world after Zoro explained the reason why Doflamingo and Caesar were after them.
After the samurai and the two rulers of Zou revealed Oden's will to open Wano Country to the world, Brook explains to Chopper how Wano Country is closed off from.
Right after Inuarashi and Nekomamushi explain that they will use the true power of the minks the next time they face the Beasts Pirates, Chopper tells Nekomamushi to take his injuries more seriously.
Kanjuro and Raizo also asking for Luffy's aid.
Franky and Chopper also encouraging Luffy to ally with the samurai in their cause.
After Kin'emon asks Luffy for his aid, the anime shows Luffy saying that he refuses more times than in the manga.
When Nami tries to embrace Momonosuke in the manga, Brook angrily states that she shouldn't. In the anime, he doesn't say anything.
Momonosuke's flashback to the day Kaido sacked the kingdom of Wano is extended, showing a large blaze started by flaming arrows, Kin'emon's panicked reaction, Lord Oden calling out while trying to escape the flames, and the instant Momonosuke's mother was slain.
When Momonosuke ran into Kaido, Kaido is shown in full and wielding his mace rather than a simple glimpse of his mouth.
Kaido's eyes are shown clearly during Momonosuke's flashback, staring down at him with hatred. In the manga, a clear view of Kaido's eyes was first shown when he was venting his rage over losing his SMILEs.
After Kin'emon comments on how Luffy treats Momonosuke like an adult, the manga showed Inuarashi saying how admirable it was. In the anime, it is Raizo instead.
Episode 770 - The Secret of the Land of Wano! The Kozuki Family and the Ponegliffs!
The anime adds the following:
Chopper asks Nami if they could find Raftel with just three of the Road Poneglyphs. Nami comments that they could not and will have to find the fourth Road Poneglyph eventually.
Jack having a flashback to his battle with Doflamingo's Marine escort. The flashback ends when Jack was about to confront Fujitora and Sengoku.
Sheepshead and Ginrummy returning to Jack.
Episode 769 - A Red Stone! A Guide to the One Piece!
From this episode on, Raizo is now featured in the We Can! intro, appearing along with Kin'emon, Kanjuro, and Momonosuke near the end.
The anime adds the following:
Luffy, Chopper, Usopp, and Franky sulking with disappointment right after seeing Raizo.
Robin asks Inuarashi if he knows about Ohara before having a flashback of the Ohara incident.
The flashback shows Robin's secret studying from the Ohara library and the researchers using a method of copying the Poneglyph writing on paper.
Franky doing his Super pose while explaining to Raizo that all men like ninjas.
While Raizo is demonstrating his shadow clone technique, Luffy tries to catch him and the ninja uses his body replacement technique.
Franky, Zoro, and Law showing amusement when Raizo finishes demonstrating his ninja abilities.
When Raizo explains that his ninja abilities are not for show, the manga only showed Luffy, Usopp, and Chopper expressing disappointment. In the anime, Franky, Zoro, and Law also express their disappointment.
Episode 768 - The Third One! Raizo of the Mist, the Ninja, Appears!
The scene with Jack is extended with Jack telling his subordinates to make his ship go faster.
Unlike the manga, Jack has been darkened during that scene.
Unlike the manga, it takes a while for Momonosuke to muster up the courage to stop Inuarashi and Nekomamushi from continuing their quarrelling.
Momonosuke's interaction with the Straw Hats is extended in the anime.
After Inuarashi and Nekomamushi form a truce, the anime adds a scene of Zunisha creating a rainbow.
Episode 767 - A Volatile Situation! The Dog and the Cat and the Samurai
The anime adds the following:
The moment Franky, Robin, and Brook wake up and commenting on Kanjuro's tiger drawing.
Sicilian ordering his fellow Musketeers to follow him and Inuarashi to the city.
The moment Luffy and his group wake up while the Guardians are heading to the city.
In the manga, Inuarashi and Nekomamushi noticed each other the moment their paths crossed. In the anime, Inuarashi was passing by Nekomamushi unnoticed, but Sicilian's shocked reaction at seeing Nekomamushi caused the two rulers to see each other.