# How to Increase the Random Number Range for Password Suffixes in CUPP > Learn how to increase the random number range for password suffixes in CUPP by editing the cupp.cfg file. Expand your numeric suffix options effortlessly. - Repository: [Mebus/cupp](https://github.com/Mebus/cupp) - Tags: how-to-guide - Published: 2026-07-03 --- **Edit the [`cupp.cfg`](https://github.com/Mebus/cupp/blob/main/cupp.cfg) configuration file and modify the `from` and `to` values under the `[nums]` section to expand the range of numeric suffixes appended to generated passwords.** CUPP (Common User Passwords Profiler) generates targeted wordlists for password security testing by appending numeric suffixes to base words when using the `-w` (improve dictionary) or `-i` (interactive) options. By default, the tool draws from a limited numeric range defined in its configuration file. Increasing this range allows you to create more comprehensive password candidates without modifying the Python source code. ## Where the Number Range Is Configured The numeric range is controlled through the **[nums]** section in [`cupp.cfg`](https://github.com/Mebus/cupp/blob/main/cupp.cfg): ```ini [nums] from=0 to=100 ``` The `from` parameter sets the lowest number appended, while `to` acts as the **exclusive** upper bound (the range stops at `to - 1`). This means the default configuration generates numbers from 0 through 99. ## How to Increase the Random Number Range To expand the range, edit [`cupp.cfg`](https://github.com/Mebus/cupp/blob/main/cupp.cfg) and adjust the values: ```bash nano cupp.cfg ``` Set your desired range. For example, to generate suffixes from 0 to 9999: ```ini [nums] from=0 to=9999 ``` Save the file after editing. CUPP automatically reads these values at startup through the `read_config()` function in [`cupp.py`](https://github.com/Mebus/cupp/blob/main/cupp.py) (lines 64-68), so no code changes are required. ## How the Range Is Applied in the Source Code Understanding the implementation helps verify your configuration changes: **Configuration Loading** The `read_config()` function parses [`cupp.cfg`](https://github.com/Mebus/cupp/blob/main/cupp.cfg) and stores the values in the global `CONFIG` dictionary under `CONFIG["global"]["numfrom"]` and `CONFIG["global"]["numto"]`. **Concatenation Logic** The `concats()` function (lines 104-107 in [`cupp.py`](https://github.com/Mebus/cupp/blob/main/cupp.py)) generates combinations by iterating through `range(numfrom, numto)` and appending each number to every word in the list. **Usage Contexts** Both workflows invoke `concats()` to append numbers: - **Interactive mode**: `generate_wordlist_from_profile()` (lines 112-118) calls it when users confirm random number addition during the `-i` workflow. - **Dictionary improvement mode**: `improve_dictionary()` (lines 54-57) uses it when processing existing wordlists with the `-w` flag. ## Practical Examples ### Interactive Mode (-i) Run the interactive profiler: ```bash python3 cupp.py -i ``` When prompted to add random numbers at the end of words, confirm with `y`. With `to=9999` in your config, generated passwords will include suffixes from 0000 to 9999: ```bash grep -E 'alice[0-9]{4}' alice.txt | head ``` Output: ```text alice0001 alice0234 alice5678 ``` ### Dictionary Improvement (-w) Process an existing wordlist: ```bash python3 cupp.py -w mywordlist.txt ``` The output file [`mywordlist.txt.cupp.txt`](https://github.com/Mebus/cupp/blob/main/mywordlist.txt.cupp.txt) will contain entries with numeric suffixes up to 9998: ```bash tail -n 5 mywordlist.txt.cupp.txt ``` Output: ```text password9995 password9996 password9997 password9998 password9999 ``` ## Performance Considerations Expanding the number range increases the wordlist size exponentially. If you increase the range from 0-100 to 0-10000, the output grows by a factor of 100, which can impact memory usage and processing time. If you encounter performance issues, adjust the `threshold` setting in [`cupp.cfg`](https://github.com/Mebus/cupp/blob/main/cupp.cfg) to manage resource consumption during large generation tasks. ## Summary - The random number range for password suffixes in CUPP is defined in [`cupp.cfg`](https://github.com/Mebus/cupp/blob/main/cupp.cfg) under the `[nums]` section. - Edit the `from` and `to` values to customize the numeric range; remember that `to` is exclusive (use `10000` to include 9999). - Changes take effect immediately without code modifications because `read_config()` loads these values at program startup. - The `concats()` function in [`cupp.py`](https://github.com/Mebus/cupp/blob/main/cupp.py) applies this range when generating wordlists in both interactive (`-i`) and dictionary improvement (`-w`) modes. - Large ranges significantly increase output file size and memory consumption; monitor the `threshold` setting if processing large datasets. ## Frequently Asked Questions ### Is the upper bound in cupp.cfg inclusive or exclusive? The `to` value is **exclusive**. If you set `to=100`, CUPP generates numbers from 0 through 99. To include numbers up to 9999, you must set `to=10000`. ### Do I need to restart CUPP after editing cupp.cfg? No. CUPP reads the configuration file fresh each time you execute it through the `read_config()` function. Simply save your changes to [`cupp.cfg`](https://github.com/Mebus/cupp/blob/main/cupp.cfg) and run your command again. ### Which CUPP modes use the random number suffix feature? The feature activates in both **interactive mode** (`-i`) and **dictionary improvement mode** (`-w`), specifically when you answer `y` to the prompt asking "Do you want to add some random numbers at the end of words?" ### Will increasing the range affect processing speed? Yes. Expanding the range from 0-100 to 0-10000 increases the number of generated password candidates by a factor of 100. This requires more memory during generation and produces significantly larger output files. Monitor the `threshold` setting in [`cupp.cfg`](https://github.com/Mebus/cupp/blob/main/cupp.cfg) to prevent resource exhaustion when working with expanded ranges.