Through the years, a few changes has been made to Recess in production or in-universe.
Note that the original pilot was not fully available for public viewing, therefore these may not be all the changes made to the show.
- Gus is not in the series
- T.J. is a tall, skinny redhead with green eyes, as opossed to being a short, chubby brunette with typical cartoon-esque black-on-white eyes (Though Word of God says his eyes are blue). His outfit is also very different; consisting of a white, green, and red t-shirt that says "T.J." on the side, jeans, and black sneakers. He does not wear his trademark baseball hat.
- Spinelli is slightly shorter than she is in the show and has her hair in multiple pigtails as opossed to two. She is also shown wearing a beige-yellow t-shirt, tan overalls, and brown shoes. She also has red lipstick and eyelashes, which she lacks in the series proper.
- Vince has a buzz cut and has a different shirt, it being a red t-shirt worn over a white long-sleeved shirt.
- Gretchen has black/dark brown hair instead of red. Her dress is off-white with green polka dots on the skirt part. The collar and trim on the sleeves of her dress are a dark pink color, which is the same color as her dress bow. Her hair bands are more "shiny" looking, and the beads are shown all around each pigtail (Such as in her Happy Meal Toy) instead of just two (Though in the series proper, this could only be for stylistic/animation purposes). Gretchen is also shown wearing red lipstick and bracelets in the pilot.
- Mikey did not go through too many changes, though his hair appears to be a little shorter and his sneakers are red instead of black.
- Dave wore a yellow neckerchief instead of a mouth mask around his neck.
- Both Diggers have white t-shirts instead of yellow as they do in the show. They also have larger and differently shaped noses than they do in the series.
- The animation has a more realistic feel to it.
- The pilot never aired on television in its' original form, but was re-made into "The Break In" for season one. Clips of the pilot were shown on a preview for ABC Saturday Mornings which advertised the premiere of Recess and 101 Dalmatians: The Series in September 1997. This advertisement was shown during ABC station identifications, and at the beginning of the tapes of 101 Dalmatians (1996), which was released in April 1997, and Doug's Birthday Blues, released in July 1997. When the clips were put on the Doug video, some confusion may have been caused, due to the final versions of the Recess Gang being leaked to the public already.
1997-1998 (Season 1)
- The animation has a darker, grittier look to it.
- T.J.'s eyes have highlights in them.
- Most of the episodes are animated by Grimsaem and Sunwoo Entertainment, both of which would continue to animate the show after the first season.
- Midway through the first season, Ashley T. begins to be voiced by Ashley Johnson instead of Rachel Crane (Who would continue to voice Ashley Q.)
- Miss Finster and Principal Prickly were more antagonistic.
1998-1999 (Season 2)
- Due to Grimsaem and Sunwoo Entertainment being busy with The Rugrats Movie, animation for most of the season was done by Plus One Animation.
- Andrew Lawrence replaces Ross Malinger as the voice of T.J., due to the latter's voice changing.
- The highlights in T.J.'s eyes are gone for unknown reasons, one reason possibly being that the highlights were difficult to animate correctly.
- Miss Grotke becomes a main character, and is added to the main character credits.
- Mundy, Skeens, Lazy Kid, Sue Bob Murphy, Kurst the Worst, and Lawson are introduced.
- "Dance Lessons" becomes the first episode to be animated by Toon City, infamous among the show's fandom for its crude, inconsistant animation.
- The colors in the artwork begins to become brighter.
1999 (Season 3)
- "Created by Paul & Joe" is added underneath the show's logo.
- Cornchip Girl becomes more prominant and is given a name in "The Bet".
- Kelso's becomes the official hangout for the Recess Gang, initially they didn't have one.
1999-2000 (Season 4)
- This season aired on UPN and in syndication as part of Disney's One Too, airing stimultaniously with season 3, which was airing on ABC on Saturday Mornings.
- This is the final season with digital animation.
- This is Toon City's last season of Recess.
- Becky Detweiler is mentioned for the first time in "Prince Randall".
2000-2001 (Season 5)
- Recess' second time slot (9:30 AM) on ABC is given to Teacher's Pet, which premiered on September 9, 2000 with the fifth season premiere of Recess.
- A shortened version of the theme song plays right after the show returns from a commercial break.
- This is the last season Hustler Kid appeared in, not counting his appearance in Recess: School's Out.
- This is the final season where new episodes premiered on ABC.
2001 (Recess: School's Out and Season 6)
- Becky Detweiler makes her first physical appearance in Recess: School's Out.
- The series was uncancelled due to the success of Recess: School's Out, however the episodes of season six were only unaired episodes of season five.
- Butch, Miss Grotke, and Principal Prickly do not appear after "The Terrifying Tales of Recess".
- The colors appear to be more washed-out than usual, such as Spinelli's orange hat being discolored as yellow.
2003 (Unaired episodes/Recess: Taking the Fifth Grade)
- The episodes of the film were initially going to be part of a seventh season/sequel series that ABC wanted to do, but Disney declined.
- The animation has switched to digital animation permanently.
- The backgrounds have a more realistic look to them, similar to Lloyd in Space.
- Myles Jeffrey becomes T.J.'s new voice actor.