This app simulates the random number generator used in Stardew Valley and makes "predictions" about the game either from the Game ID or by reading the save file. Currently, the information predicted includes special mine levels (e.g. mushroom floor & infestations), random items sold by some vendors, results from cracking geodes, the train schedule, and more. A useful companion tool is BlaDe's Map Predictor which handles things such as artifact digging, giant crops, and mine ladders.
All changed & added content from version 1.6 should be supported; 1.6-specific features will only appear in the results if either the save is detected to be from that version or the app is launched with a URL id parameter.
The app is written in Javascript and uses jQuery, BigInteger.js, JS xxHash, and pako; it is hosted on GitHub Pages at https://mouseypounds.github.io/stardew-predictor/ and the source code repository is https://github.com/MouseyPounds/stardew-predictor. It is released under the MIT license.
Please report any bugs, suggestions, or other feedback to the topic in the Stardew official forums or to @mouseypounds on Discord.
20 Apr 2024 - v5.0.8 - Fixed advanced usage breaking after last update; better mp sanity-checking
18 Apr 2024 - v5.0.7 - One more seed overflow fix, changes for patch 1.6.4, support for compressed Switch saves
7 Apr 2024 - v5.0.6 - Variety of PR bugfixes
6 Apr 2024 - v5.0.5 - Bugfix for invalid ID in URL; marked Sandy shirts that are otherwise hard to acquire
4 Apr 2024 - v5.0.4 - Bugfixes for Prize Tickets, first 10 mystery boxes, and Calico Jack dealer draws
30 Mar 2024 - v5.0.3 - Finally added slightly more friendly error-handling
28 Mar 2024 - v5.0.2 - Fixed precision loss bug in enchantment code
27 Mar 2024 - v5.0.1 - Update cart item lists for 1.6.3 patch
26 Mar 2024 - v5.0.0 - Support for Stardew Valley 1.6
15 Jan 2021 - v4.0.4 - Updating Night event chances for Stardew Valley 1.5.3
9 Jan 2021 - v4.0.3 - No code changes, only clarifications on some mechanics.
30 Dec 2020 - v4.0.2 - Made geode fix only apply to 1.5 saves
28 Dec 2020 - v4.0.1 - Fixed geode predictions
22 Dec 2020 - v4.0 - Initial support for Stardew Valley 1.5
24 Jul 2020 - v3.1.3 - Updated forum link in footer
6 Mar 2020 - v3.1.2 - Fixed Krobus search
1 Feb 2020 - v3.1.1 - Fixed one of the white eggs in the cart prediction being incorrectly listed as brown. (Thanks rickselby)
29 Dec 2019 - v3.1.0 - Added Skull Cave Dino levels to Mine info and a new tab for Garbage Can loot; also some fixes and formatting changes
13 Dec 2019 - v3.0.3 - Another small version error regarding artifact troves in search results
7 Dec 2019 - v3.0.2 - Version detection changed again to handle semver like 1.4.2
30 Nov 2019 - v3.0.1 - Version detection should now properly identify day one 1.4 saves
26 Nov 2019 - v3.0 - Support for Stardew Valley 1.4
5 July 2019 - v2.2.1 - Fixed a wiki link error.
30 Jan 2019 - v2.2 - Improved support for iOS save files
24 Oct 2018 - v2.1 - Added Wallpaper predictions and moved images to spritesheets
3 Oct 2018 - v2.0.2 - Bug fixes for Winter Star processing when using URL ID parameter instead of a save
1 Sept 2018 - v2.0.1 - Collapse older entries in changelog
20 Aug 2018 - v2.0 - Added Krobus tab (thanks ronw23 on GitHub). Better input sanitization for anti-Cat protection
18 Aug 2018 - v1.8 - Added public domain BigInteger library; MP support and fixed predictions for Winter Star 1.3
17 Aug 2018 - v1.7.1 - Added warning about broken Winter Star predictions in 1.3
17 Aug 2018 - v1.7 - Small bugfix on Geode predictions for 1.3
24 May 2018 - v1.6 - Favicon; Baby question for 1.2 save night events
23 May 2018 - v1.5.1 - Clarification in Night event intro & disclaimer about 1.2
21 May 2018 - v1.5 - Night events added; list potential Winter Star gifts
7 May 2018 - v1.4 - Geode counter bugfix; additional multiplayer support
6 May 2018 - v1.3 - Traveling Merchant now includes Night Market if save is from 1.3
4 May 2018 - v1.2 - Days Played bugfix
14 Apr 2018 - v1.1 - Train schedule added
7 Mar 2018 - v1.0 - Full release, searching for geodes added
4 Mar 2018 - v0.94 - Rewrite of RNG class to avoid ES2015-specific features for Pale Moon compatibility
3 Mar 2018 - v0.93 - Indicator for geode contents which need donation
25 Feb 2018 - v0.92 - Fixing Baryte spelling and double-button processing bug
22 Feb 2018 - v0.91 - Search for Cart items, Winter Star bugfix
20 Feb 2018 - v0.9 - Beta Testing
4 July 2017 - v0.5 - Alpha Testing