## 5.16.2 - 10th of October, 2021

1. Improved server application performance.

   Analyzed db performance using [eversql.com](https://eversql.com).
   Thank you Tomer!

   Hopefully you will experience a quicker regex library and website over all!

## 5.16.1 - 10th of October, 2021

1. Fix regression when painting match results on canvas (thanks digitok for reporting)

## 5.16.0 - 8th of October, 2021

1. Add support for named backreferences in JS substitution mode. See [https://github.com/firasdib/Regex101/issues/1652](https://github.com/firasdib/Regex101/issues/1652)

2. Fix parsing of escaped dollar signs in JS substitution mode.

3. Add tests to task 15. See [https://github.com/firasdib/Regex101/issues/1645](https://github.com/firasdib/Regex101/issues/1645)

## 5.15.3 - 8th of October, 2021

1. Improve error handling of recursion related errors

2. Improve handling of escaped text literals and unicode

3. Update codemirror to latest version

4. Updated translations

5. Improved handling of links in the header on smaller screens

## 5.15.0 - 22nd of September, 2021

1. Added support for new `d` flag in JavaScript

## 5.14.1 - 3rd of September, 2021

1. Fix collating posix class parsing

2. Ensure `performance` is polyfilled properly

## 5.14.0 - 9th of August, 2021

1. Slightly darken theme color for the light theme

2. Add new option to disable the default tabbing behavior.

   This options allows you to decide what should happen when you hit the tab key:

   1. Switch to the next field in the document (default)

   2. Consume the tab key and insert a tab character

3. Fix explanation of `\P`

## 5.13.6 - 31st of July, 2021

1. Add separate meta descriptions for the different sub pages

2. Fix tooltip direction switching randomly in the account page

3. Improve error handling when `\C` is used

4. Fix character range check for surrogate pairs

## 5.13.5 - 26th of July, 2021

1. Copy behavior of Perl and disallow \K inside lookbehinds in PCRE. See [https://bugs.exim.org/show_bug.cgi?id=2792](https://bugs.exim.org/show_bug.cgi?id=2792)

2. Fix minor issues with lookbehind length calculation in edge case scenarios

3. Update quote token color in dark theme

## 5.13.4 - 18th of July, 2021

1. Fix issue where the scroll bar was unnecessarily shown for library entries

2. Fix issue where page sometimes became non-interactable [https://github.com/firasdib/Regex101/issues/1618](https://github.com/firasdib/Regex101/issues/1618)

## 5.13.3 - 13th of July, 2021

1. Format large numbers to make them easier to read

2. Code generator button is now disabled when in List Substitution mode to avoid confusion

3. Fix posix class parser for PCRE and PCRE2

## 5.13.2 - 11th of July, 2021

1. Added tooltip to match indicator when unhandled errors are encountered (hover to view)

2. Fix explanation of `\Q...\E` [https://github.com/firasdib/Regex101/issues/1614](https://github.com/firasdib/Regex101/issues/1614)

## 5.13.1 - 10th of July, 2021

1. Plain text explanation now shows code points in decimal, hex and octal

   The explanation is collapsed by default to avoid creating too much noise.

2. Plain text in the substitution box is now explained in a similar fashion to the regex input

3. Adjusted styling and timing of tooltips

   - Timing of tooltips has been adjusted slightly, they now trigger faster
   - A drop shadow has been added to give them a bit of depth
   - The closing animation for tooltips were broken, its now fixed
   - Performance of tooltips has been improved slightly by using composite layers in the browser

## 5.13.0 - 7th of July, 2021

1. Fix regex parsing of relative subpattern references

2. Handle error caused by nesting too many conditional replacements in PCRE2

3. Disallow null bytes in regex

4. Use high precision timers for calculating computational time spent in regex

5. Update favicon and add more PWA support

## 5.12.3 - 6th of July, 2021

1. Fix java subst pattern parsing (hopefully once and for all)

2. Fix subst conditional coloring not repeating properly

3. Reworked substitution area to be more efficient. If you encounter any odd behavior, please report it as a bug on github.

## 5.12.2 - 5th of July, 2021

1. Improve paste performance further

2. Fix issue with Java code generator [https://github.com/firasdib/Regex101/issues/1611](https://github.com/firasdib/Regex101/issues/1611)

3. Remove the `2.7` part from the python flavor text

4. Improved performance on initial page load

## 5.12.1 - 1st of July, 2021

1. Fix issue with `\Q...\E` when pasting regexes into the regex box (Thanks digitok)

2. Disallow `\C` in lookbehinds in PCRE when enabling UTF16 mode

3. Error if user places unescaped `{` inside conditionals in PCRE mode during substitution

4. Fix numeric escapes sometimes not working in java substitution mode

5. Update codemirror to latest version

6. Fix lookbehind length calculation in x-mode

7. Add proper surrogate pair parsing for java flavor

## 5.12.0 - 25th of June, 2021

1. Fixed typo in quickref for charclass intersection [https://github.com/firasdib/Regex101/issues/1598](https://github.com/firasdib/Regex101/issues/1598)

2. Add support for `LD` unicode script in Java [https://github.com/firasdib/Regex101/issues/1590](https://github.com/firasdib/Regex101/issues/1590)

3. Fix issue where relative backreferences could reference invalid groups

4. Fixed issue where nested branch reset groups would not validate properly

5. Added indicator for zero width character matches [https://github.com/firasdib/Regex101/issues/1593](https://github.com/firasdib/Regex101/issues/1593)

6. Generate error when `\E` is encountered without a corresponding `\Q`

7. Fix edge case in inline modifier parsing for Java flavor

8. Disallow quantifiers inside lookbehinds for Python flavor

9. Fix issue where unknown unicode categories were accepted for Java

## 5.11.3 - 23rd of June, 2021

1. Fix potential race condition when initially loading the page

2. Add word-wrapping to user submitted descriptions to avoid page overflow issues

## 5.11.2 - 11th of June, 2021

1. Fix issue where quantifiers on certain tokens did not visually show up in explanation

## 5.11.0 - Xth of May, 2021

1. Fixed issue where `\8` and `\9` would not work in Java substitution strings

2. Updated IRC link to Libera

## 5.10.0 - 12th of May, 2021

1. Fixed general unicode category for Java [https://github.com/firasdib/Regex101/issues/1570](https://github.com/firasdib/Regex101/issues/1570)

2. Added new delimiters to javascript flavor

3. Added highlight in regex input when clicking a group in the match info pane

4. Emphasize negative unit tests with an underline

5. Added nbsp to explanation for `\s` for python flavor

## 5.9.0 - 19th of April, 2021

1. Added ability to delete your account

## 5.8.0 - 10th of April, 2021

1. Added support for all verbs in PCRE2

2. Fixed parsing of inline modifiers in golang [https://github.com/firasdib/Regex101/issues/1551](https://github.com/firasdib/Regex101/issues/1551)

3. Fix library url after uploading entry

4. Fix "My Library Entries" showing favorited entries

5. Highlight the `not` part of the does not match in unit test

6. Fix left sidebar options after updating library entry

7. Fix error handling when using `\C`

8. Fix debugger not handling empty data results

9. Made `\E` not quantifiable

10. Fixed some unicode property names for Java

11. Fixed unit tests sometimes not running when they should due to race condition

12. Remove truncating alternator check [https://github.com/firasdib/Regex101/issues/1556](https://github.com/firasdib/Regex101/issues/1556)

## 5.7.1 - 24th of March, 2021

1. Disallow backreferences inside character classes in Java

2. Fix binary unicode properties in Java

## 5.7.0 - 23rd of March, 2021

1. Fix explanation of character class intersection for Java

2. Fix regression in paste behavior [https://github.com/firasdib/Regex101/issues/1536](https://github.com/firasdib/Regex101/issues/1536)

3. Hardened verification for relative subpattern references

## 5.6.2 - 22nd of March, 2021

1. Fixed issue with `?` shortcut on certain devices [https://github.com/firasdib/Regex101/issues/1529#issuecomment-797851128](https://github.com/firasdib/Regex101/issues/1529)

2. Fixed regression in lookbehind quantifier validation for the PCRE flavor

3. Removed `\n` from substitutiton tokens in the quick reference for PCRE2

4. Hardened Java named backreference checker

5. Updated text displayed when browser is deemed too old to explain what is missing.

## 5.6.1 - 18th of March, 2021

1. Fix flags not explained when declared in group construct

2. Fix animation of left sidebar

3. Fixed link in match error section after engine fails to load

4. Fixed resize observer spamming error logs in quiz page

## 5.6.0 - 16th of March, 2021

1. Improved error handling

2. Disabled the use of `\k` in character classes in JS to avoid errors in certain browsers

3. Fixed issue when voting on certain library entries

4. Fixed Unicode escapes `\uNNNN` in java, accidentally accepted `\u{NNNN}` syntax

5. Disabled the use of quoted literals without any content as that has some ambiguous behavior

6. Fixes explanation regression [https://github.com/firasdib/Regex101/issues/1531](https://github.com/firasdib/Regex101/issues/1531)

## 5.5.3 - 15th of March, 2021

1. Fix regression in Javascript unicode parsing [https://github.com/firasdib/Regex101/issues/1530](https://github.com/firasdib/Regex101/issues/1530)

2. Add variable width lookbehind support to Java.
   The quantifiers `*` and `+` are disabled due to dodgy support in Java 8.
   In later versions (13+), the full regex syntax is supported (including backreferences).
   For now, neither backreferences nor the mentioned quantifiers will function in Java 8 on regex101

3. Fixed regression where `[^]` wasn't colored in JS mode

4. Fixed bug where unit tests were not ran if the regex switched from an error state to a non-error state

5. Disabled spell check for certain inputs where it was unnecessary/intrusive

6. Added clear indicator whether any test failed in the unit test view

7. Fixed subpattern parsing in subst mode for PCRE2

8. Fixed edge case when parsing java character classes that could result in `]` being treated literally

9. Fixed replacement in Java no handling trailing backslash properly

## 5.5.2 - 14th of March, 2021

1. Remove Disqus from library comments due to obscene ads

2. Handle stack overflow errors in Java

## 5.5.1 - 13th of March, 2021

1. Fixed parsing of `\R` in Java

2. Fixed parsing of named groups in Java

3. Updated some quickref entries

4. Fixed parsing of `\c` in PCRE2

5. Fixed parsing of whitespace while using the `x` flag in Java

## 5.5.0 - 12th of March, 2021

1. Made descriptions mandatory for library entries

2. Fixed library page not showing vote state on initial load

3. Added vote buttons to library details page to make voting easier

## 5.4.0 - 10th of March, 2021

1. Fixed issue where zero width match could erase the color of a same match at the same position

2. Added support for Java

3. Improved explanations for substitution tokens

4. Improved performance of the explanation engine

5. Increased contrast of white space visualization

6. Added link to regular-expressions.info when expressions time out

7. Fixed the PCRE2 substitution parser not catching all invalid escape sequences

## 5.3.1 - 6th of March, 2021

1. Fix issue with group painting when `\K` was used

2. Reduce size of export match button; makes it less obtrusive in the UI

3. Fix match info table on smaller screens

4. Fix monospaced font not applied properly in test area tooltips

5. Fixed explanation for `\b` being double escaped

## 5.3.0 - 5th of March, 2021

1. Updated the token colors for both themes. They are now easier on the eyes and aligned between the two.

2. Adjusted size of tooltips in editor

3. Adjusted the wording of tooltips when hovering regex tokens in the editor

4. Adjusted how \Q...\E is parsed and visualized in the editor.

5. Reworked the match information panel and made the space usage a bit more efficient. Reduced the amount of coloring in that region as well.

6. Updated styling of explanation area with regards to which items are highlighted and how.
   The goal is to reduce eye strain and color overload, and only color things that matter.

7. Adjusted wording in some of the explained entries.

8. Updated some entries in the quickref related to PCRE2 modifiers

9. Increased size of match export modal

10. Fix menus not easily closable on mobile

11. Fixed issue with library refetching entries unnecessarily

12. Added opengraph meta tags to index.html

13. Switched to source code pro as it seems to render better

14. Increased stroke contrast when hovering a match

## 5.2.8 - 25th of February, 2021

1. Adjusted how loading is done for sub-pages (no more blurring)

2. Quiz now makes a reduced amount of API calls for a better user experience

3. Fixed vote buttons on library page being incorrectly focusable

4. Improved contrast on library page

5. Increase size of quiz statistics chart

## Version 5.2.7 - 23rd of February, 2021

1. Updated relevance sorting algorithm for library page

2. Fixed bug where searches would randomly stop working on library page

3. Fixed race condition in list substitution mode for js flavor

4. Library entries now show their title in the header of the modal instead

5. Made the group numbers in the match info area focusable using tab

6. Added link to the debugger when catastrophic backtracking is detected

7. Automatically focus the input field in library view

8. Added button to easily navigate to library entry from regex editor

9. Improved load times of the website and placed theme code earlier in execution pipeline to avoid incorrect theme flashing

10. Fixed explanation of `\S` and `\W` in unicode mode.

11. Automatically set document title for the different parts of the website

12. Avoid transition flicker when loading pages on a fast connection

13. Add clear button to certain inputs

14. Update server configuration for better performance all around

15. Fix bug where small screens would not properly resize the substitution area

16. Fix issue where canvas would not repaint after closing the substitution area

## Version 5.2.5 - 21st of February, 2021

1. Reduced initial bundle size by code splitting more components that are not immediately necessary

2. Fixed focus outline of treeview arrows

3. Removed react-dom-server dependency (upstream react bug has since been fixed), further reducing bundle size

4. Improved accessibility of buttons by adding disabled attribute where applicable

5. Fixed surrogate validation for octal escapes

6. Switched to new service worker plugin, hopefully this works better!

7. Fixed multiple obscure issues reported by sentry, making the app more stable.

8. Added indicators to unit tests, alleviates some of the trouble color blind people might have with the new design. See [https://github.com/firasdib/Regex101/issues/1514](https://github.com/firasdib/Regex101/issues/1514)

## Version 5.2.0 - 16th of February, 2021

1. Added list substitution feature [https://github.com/firasdib/Regex101/issues/1410](https://github.com/firasdib/Regex101/issues/1410)

2. Increased font sizes throughout the app

3. Improved contrast ratio for dark theme

4. Fixed light theme flashing when loading website and dark theme was previously selected

5. Improved tooltip for conditionals [https://github.com/firasdib/Regex101/issues/1503](https://github.com/firasdib/Regex101/issues/1503)

6. Signing in will now save the state of the regex editor and restore it upon returning to the website.

7. Revamped unit test area [https://github.com/firasdib/Regex101/issues/1090](https://github.com/firasdib/Regex101/issues/1090)

8. Added new shortcuts. Hit `?` when not inside an editor. [https://github.com/firasdib/Regex101/issues/1088](https://github.com/firasdib/Regex101/issues/1088)

9. Improve text selection color

10. Increased the regex debugger domain to [0, 200] by default, instead of [0, 50]

11. Fix substitution area running match on mount with invalid substitution string

12. Fixed regex parser regressions

13. Switched monospace font to roboto mono

## Version 5.1.8 - 11th of February, 2021

1. Updated the display of the quiz statistics

2. Added method to revalidate quiz entries when the tests change

3. Fixed explanation for the `A` flag for PCRE/PCRE2 [https://github.com/firasdib/Regex101/issues/1498](https://github.com/firasdib/Regex101/issues/1498)

4. Fixed an issue where codemirror would cause a layout shift when initially rendered

5. Made JS `y` flag and PCRE `A` flag interchange when switching flavors [https://github.com/firasdib/Regex101/issues/1499](https://github.com/firasdib/Regex101/issues/1499)

6. Fix issue where the toolbar for the unit tests was shrunk down

7. Automatically switch to the unit test pane if there is no test/substitution string [https://github.com/firasdib/Regex101/issues/1502](https://github.com/firasdib/Regex101/issues/1502)

## Version 5.1.2 - 8th of February, 2021

1. Fixed regression in match highlighter [https://github.com/firasdib/Regex101/issues/1495](https://github.com/firasdib/Regex101/issues/1495)

2. Fixed issue where save modal would not highlight the value

3. Fixed issue where copy buttons would stop working

## Version 5.1.0 - 8th of February, 2021

1. Add code splitting
    - Split out large dependencies
    - Conditionally load polyfills
    - Lazy load certain components

    This might result in a few more quirks and bugs, but they will be ironed out with time.
    Please report any findings on [github](https://github.com/firasdib/Regex101/issues)

2. Remove large (unnecessary) dependencies

    Bundle size for initial load has been shrunk by around 30% with the above change.

3. Update PCRE2 to solve issue of number parsing (PHP and other implementers will have to do the same eventually)

4. Full rewrite of many components to improve accessibility
    - Tabbing is context aware
    - Navigation of entire site through tab
    - Aria tags added (not exhaustive, will be ongoing work)

    Hopefully this improves the experience for everyone!

5. Fixed issue where test area would not accurately highlight all strings

6. Fixed an issue where the markdown editors toolbar did not work as intended

7. Fixes links in quickref [https://github.com/firasdib/Regex101/issues/1489](https://github.com/firasdib/Regex101/issues/1489)

8. Removes duplicate entry in quickref [https://github.com/firasdib/Regex101/issues/1493](https://github.com/firasdib/Regex101/issues/1493)

9. Fixed issue where closing substitution area did not properly update the match coloring

10. Adds preloading to fonts and web worker


## Version 5.0.21 - 3rd of February, 2021

1. Fixed infinite loop when loading the page and subst box was open

2. Improve screen readers and SEO

## Version 5.0.19 - 2nd of February, 2021

1. Fix substitution area not triggering initially when opened

2. Fix subst indicator clipping

3. Fix subst area sometimes using invalid regex when performing subst (using cache is great...)

4. Fix issue where test input would not reset focus state

## Version 5.0.16 - 31st of January, 2021

1. Fixed backend not allowing users to unfavorite permalinks

2. Added ability to edit permalink details if signed in for favorited expressions through the save modal

3. Adjusted color for the resize strip in the right sidebar

4. Fixes validation of (?P>...) in PCRE

5. Added check to ensure null bytes aren't included in the regex for PCRE

## Version 5.0.13 - 30th of January, 2021

1. Add check to ensure numbers following backslashes are not too large

2. Update the default flavor to PCRE2

3. Explain `\s` and `\S` for javascript using unicode tokens instead of literal text

4. Fix substitution not running if test string was empty

5. Add support for non atomic lookarounds

## Version 5.0.12 - 28th of January, 2021

1. Fixed issue where the same input pasted into the regex input would not highlight syntax.

2. Treats `$$` as escaped literal in PCRE2 subst string

3. Fixed regression in `{m,n}` quantifier validation

4. Fixed invalid backref parsing for pcre2 (`\80` to `\99` was interpreted as ocals and literals)

5. Align the PCRE2 implementation with pcre2test wrt to empty matches at the end of the string

6. Fix text input focus issue [https://github.com/firasdib/Regex101/issues/1482](https://github.com/firasdib/Regex101/issues/1482)

7. Fix tags/titles not saved correctly

8. Show delete link in save modal for users who are not signed in

## Version 5.0.11 - 25th of January, 2021

1. Fixed bug in regex parser [https://github.com/firasdib/Regex101/issues/1477](https://github.com/firasdib/Regex101/issues/1477)

2. Added support for new PCRE2 features [https://github.com/firasdib/Regex101/issues/1476](https://github.com/firasdib/Regex101/issues/1476)

3. Updated tests for quiz task 27

4. Fix save modal not always selecting the generated url

## Version 5.0.10 - 24th of January, 2021

1. Patched numerous bugs that slipped through the initial release.

2. Updated quiz task 11 and 27 (Thanks David!)

3. Fixed issue with match timeout setting not working as intended

4. Increased memory limits for PCRE, PCRE2 and Python.

## Version 5.0.0 - 22th of January, 2021

1. Rewrote entire backend to improve performance

2. Reworked the account page; titles and tags are now associated with the entire
permalink and not a specific version.

3. Redesigned the save modal, it now shows the account information (if signed in) in the same view,
and makes it easier to work with.

4. Switched to new icons throughout the entire application

5. Slight modifications to the general look and feel, such as flatter buttons and larger font sizes.

6. Added support for PCRE2

7. Dropped support for legacy browsers, approximately the following versions: Internet Explorer, Firefox <55, Chrome <60, Edge <16

8. Reworked library entries: a permalink is now permanently associated with an account and the
entry, and the owner can whenever they want update the version of that permalink which will reflect
in the library. Hopefully this is not going to be abused, but if it is, the library will always
default to the first version and never allow for an update.

9. Titles and tags are now associated with the entire permalink and all versions within it.

10. The default save functionality of the website has been changed, now a new permalink is created
by default (using ctrl+s) and an update of the current workspace has to be explicit,
by either clicking the menu item or using ctrl+shift+s.

11. The regex quiz now utilizes the PCRE2 engine instead of PCRE1.
Can you exploit this to your advantage?

12. Multiple dependencies has been updated, which has resulted in a lot of behind-the-scenes work.
This has resulted in general performance improvements, but nothing you are likely to experience.

13. Squashed 20-30 different edge case bugs in the app and regex tokenizer.
I will outline fixes of this nature in the future, but for now, take my word for it.

14. The supported Python version is now indicated in the sidebar

15. Reorganized settings

16. Added a new setting that allows you to conditionally turn on/off step counting in supported
flavors. This can dramatically improve performance in complex expressions.

17. Fixed key binding bug which would present itself in the debugger.

18. Added more tests to multiple quiz tasks.

19. Implemented surgical fix to avoid odd tabbing behavior in debugger (and other similar modals)

20. Added support for the # delimiter.

21. Due to 2 and 8, the database had to be modified, and data had to be migrated.
Some loss of data is to be expected, since not all the information from the previous model could
fit in the new one, but there are extremely few individuals affected.
This only affects titles and tags, not any saved expressions.

22. Fixed autoit code generator

23. Fixed parsing and validation of surrogate pairs in the editor

24. Added a "whats new" button to the header

25. Revised contrast of dark theme

26. Increased font sizes slightly

27. Improved performance of tooltips in the editor (and possible squashed a few bugs that would cause the app to crash)

28. Rewrote large parts of the editor page (front page) and the regex parser. Hopefully I have not introduced (too many) new bugs...

29. Substitution area has received some love. A new indicator was added, similar to the match functionality.

30. Added PCRE2 native substitution (and the new syntax).

31. Fixed bug with `\b` in substitution