Data-Logs will be organized by level, and titled as followed:
If you a missing a specific Data-Log, you can search for the missing #. Otherwise, consult the World board in the museum for incomplete levels.

A majority of the data-logs will require you to have some way to reach high places. This can include:

• The Rocket Pants triple jump
  
• The Jetpack
  
• The Pogostick
  
• The Grappling Hook
  
• Rocket jumping via the Commando's Rocket ability
  
• Rocket jumping via an explosive weapon

Data-logs found in such places will be listed as requiring a "Jump Upgrade".

Some data-logs will require you to have the shovel equipped to dig up the data-log. These dig spots can be hard to see and sometimes even spawn inside walls. It's recommended to save these data-logs for last, and use the Metal Detector gadget once unlocked for easy locating.

Some data-log locations are also randomized across save files. They can spawn in a general area, which the guide will describe.

The final data-log in Haven City will require all six power crystals.

EDIT: If it looks like an image is missing, it's because Steam is having a stroke and deleting random images from guides. Sorry.

Requirements: None
Random: No
Location: The starting room inside a radio antenna.

Requirements: None
Random: No
Location: Directly above the starting door is a data-log. As pointed out by paul_entah, ff you don't have a jump upgrade you can do a bit of parkour to reach the ledge.

Requirements: Jump Upgrade
Random: Yes
Location: Placed on the upper level somewhere on the level will be a camp with a data-log.

Requirements: Jump Upgrade
Random: No
Location: Right before the mid safe room, jump up to the upper area to find Buddybot's campsite.

Requirements: None
Random: No
Location: Right before you enter the Oasis will be a radio antenna. Open it to find the data-log.

Requirements: Ruins Key
Random: No
Location: Right after you enter the Ruins route, the data-log will be on a cliff directly behind you. There are metal platforms on the edge of the canyon walls that will let you jump up to it.

Requirements: Quarry Key, Jump Upgrade
Random: No
Location: Before entering the door to the dig site, jump up to the upper area. There will be an opening in the right side, where a data-log will be hidden.

Requirements: Shovel
Random: Yes
Location: A random dig site will contain a data-log.

Requirements: Buddybot
Random: No
Location: Inside the locked room behind the waterfall. You will need to find Buddybot and have it equipped to open the door.

Requirements: Jump Upgrade
Random: Yes
Location: In the first main area before the mid safe area (the big circle where the corrupted area and Johnny Waterfall can be found. Up on a ledge will be a small camp, which can be seen from the ground when looking up.

Requirements: Jump Upgrade
Random: No
Location: In the back of the secret area where you can find Johnny Waterfall will be a ledge way up high. On top will be the data-log. Even if you on;y have an explosive weapon, you can pick up the data-log by getting close enough to the edge of the ledge.

Requirements: None
Random: No
Location: Tucked into a corner of the mid safe room.

Requirements: None
Random: No
Location: Right before the mid safe room of the Oasis will be an antenna. The data-log is inside.

Requirements: Shovel
Random: Yes
Location: Randomly placed, must be dug up.

Requirements: Jump Upgrade
Random: No
Location: Upon entering the Ruins, the data-log will be directly up behind you.

Requirements: None
Random: No
Location: Upon leaving the Ruins starting room, the data-log will be to your right up high behind a car.

Requirements: Ruins puzzle completion (None)
Random: No
Location: Inside the secret area in Ruins will be a dead robot. Interact with it to find the data-log.

Requirements: None
Random: No
Location: Inside the mid safe area, behind a rock wall.

Requirements: Jump Upgrade
Random: Unknown
Location: Inside a moss covered pipe near the corrupted area.

Requirements: Jump Upgrade
Random: Yes
Location: Inside a radio antenna past the second arena fight, up high on a ledge.

Requirements: Jump Upgrade
Random: No
Location: Inside the starting room, jump up to the upper area behind you to find a data-log inside a radio antenna.

Requirements: Jump Upgrade
Random: Yes
Location: In the first section of the map will be a camp on the upper area. You will not hear electro-swing nearby.

Requirements: None
Random: No
Location: In the first section of the map will be a radio antenna with a data-log inside.

Requirements: None
Random: Yes
Location: In the room before the final boss.

Requirements: Secret area door code
Random: No
Location: Inside the secret area will be a hole with a data-log at the end.

Requirements: Jump Upgrade
Random: No
Location: Directly behind where you spawn, way up top.

Requirements: Jump Upgrade
Random: No
Location: Next to the corrupted area, on a ledge up high.

Requirements: Jump Upgrade
Random: Yes
Location: In the first section of the map will be a campsite on the upper area with the data-log.

Requirements: Jump Upgrade
Random: No
Location: Inside the locked tech room in the mid safe room, in a small duct.

Requirements: Shovel
Random: Yes
Location: Buried in a random dig spot.

Requirements: Jump Upgrade
Random: No
Location: Outside the door to the Waste Station. This is in the upper-right corner of the room right before the mid safe room, hidden behind some vines.

Requirements: None
Random: No
Location: Inside the mid safe room.

Requirements: None
Random: No
Location: Also inside the mid safe room, on a ledge next to the exit.

Requirements: Jump Upgrade
Random: No
Location: Inside the arena down the route to the Energy Center, on the upper area.

Requirements: None
Random: No
Location: Right next to the exit door to the Energy Center.

Requirements: Elemental Code
Random: No
Location: After getting the full code from the Tech Lab, open the door at the start of Energy Center. The data-log will be in a hole at the back of the room.

Requirements: Jump Upgrades
Random: Yes
Location: On the upper area of the first part of the level will be a camp with the data-log.

Requirements: None
Random: No
Location: After entering the mid safe area, there will be a small corridor next to Med ♥♥♥. The data-log can be found at the end.


Requirements: Tech Lab Key
Random: No
Location: After entering the mid safe area, there will be a locked door. The key can be found after exiting the level "Doom Gardens" and entering the Aqua Gardens. Inside the room will be a hole where the data-log can be found.

Requirements: None
Random: No
Location: Inside the room before the boss tucked into a corner.

Requirements: None
Random: No
Location: Top of the spawn room, to the left.

Requirements: None
Random: Yes
Location: There is a camp randomly placed on the upper area of the level with the data-log.

Requirements: None
Random: ♥♥♥♥ Yes
Location: This one is tucked away in a back corner of the map. A random corner. Just run around the edges of the marked areas on your map.

Requirements: Red Ticket
Random: No
Location: Inside the Cinema, at the back.

Requirements: Blue Ticket
Random: No
Location: Inside the Museum, directly above the entrance.

Requirements: Green Ticket
Random: No
Location: Inside the Stadium, directly above the entrance.

Requirements: None
Random: No
Location: Outside the secret area (yellow on minimap).

Requirements: All 6 Crystals
Random: No
Location: Inside the secret area (yellow on minimap).

Requirements: None
Random: No
Location: Next to one of the corrupted areas.

Requirements: None
Random: No
Location: Next to the other corrupted area.

Requirements: Jump Upgrade
Random: No
Location: In the room before the boss, to the right on top of a ledge