Fiddler Classic

Release History

Fiddler v1.x

Jan 20, 2014

Fiddler v1.x


Note: Fiddler v1.x has been retired; all future updates will only be made for Fiddler v2, above.

Version - Released 6/1/07.

Many bugfixes
Updated SampleRules.js
Improved Inspectors; WebForms, Hex were major rewrites
Improved performance-timers
Added Timer calculations to Performance Statistics tab
Added Password-protected archive option; Click the "Save As Type" dropdown on the Save Dialog

Version - Released 4/13/07.

Improved inspectors & AutoResponder
Changed ZipArchive to use .SAZ file extension
Introduced AutoFiddler extensibility interface
Performance improvements
Many bugfixes and improved error messages

Version - Released 1/30/07.

New AutoResponder features simplify tampering
Many new rules; added Performance submenu to Rules menu
Improved QuickExec box below session list (type HELP)
Improved Inspectors; added IAutoFiddle support
Improved Reporter tab with chart improvements
Improved TextEncoder
Improved options dialog
More flexible Request builder
Improved Visual Studio WebTest export
Improved RFC2616 support
Performance improvements
Many bugfixes and improved error messages

Version - Released 8/20/06.

Many bug fixes
Added InfoTip if response is encoded
Added Authentication Inspector
Session Properties view shows # bytes downloaded (helpful when downloading huge files through Fiddler. Hit F5 to refresh)

Version 1.2.0 - Released 6/29/06.

Fixes to support Windows Vista
Improved support for Rules Menu items
New version check feature
Header inspector enables editing all headers at once
Significant performance improvements

Version 1.1.9 - Released 5/18/06.

Added QuickExec box (Hit Alt+Q)
IPv6 Literal Support
Support for request chunking
Performance Report improvements
Web-Test Export Bugfixes
ImageViewer improvements (e.g. Middle+Click to dump image to desktop)
Added FontSize to Options dialog
Added lightweight Request Form viewer
Added HideOnMinimize option
Created ExecFiddlerAction.exe for use by command line tools wishing to drive Fiddler
Added actResumeAllSessions()
Added "GetTokenValue" to HTTPHeaders object
Dozens of miscellaneous bugfixes

Version 1.1.6 - Released 3/1/06.

Introduced support for upstream proxy autodetection and configuration scripts (http/https delivered scripts only)
Enhanced Find Sessions feature with new options
Added "Clone response" to session context menu
Fixed upstream NTLM/Negotiate proxy support
When DebugSpew is on, both requests and responses dumped to debug console in hex format
Change default for CaptureCONNECT to True
Added FiddlerObject.UI.actReloadInspectors() added to simplify inspector development
Fixed Save as WebTest in various ways
Allow userscript to override the hostname used to determine upstream IP, without changing the HTTP headers. This enables HOSTS-file type scenarios where a request should be sent to an alternative server.  e.g. in your OnBeforeRequest() handler, put code like: if ("") { oSession["x-overrideHost"] = "" }  Obviously, this doesn't work if you have an upstream proxy, and you have to just tweak directly for those cases.
Performance and Robustness improvements

Version 1.1.0 - Released 11/29/05.

Critical security update
New View | Stacked Layout option
Autobreakpoints now ignore images by default
Image inspector offers two scaling modes
Insert key marks current session
Prompts to install WinDiff if Session Compare can't find it
String registry entry "CompareTool" enables custom Compare tool choice
Autobypass upstream proxy for hostnames "" and "localhost" (only downside is can't chain instances)
.NET Framework v2.0 now detected by installer

Version 1.0.5 - Released 11/15/05.

Rebuilt proxy registration code to ensure Fiddler leaves settings as it found them
Hex inspector again installs as it now works on Windows Vista beta2.
Slight tweaks to default session colors
Changed file-save dialogs for clarity
Script can set state to SessionStates.Done to abort further processing
Improved NTLM handling (It's now believed to be bug free!)
Updated Session Archive feature
Changed default for Server socket reuse to ON
Updated Find Sessions form to automatically cycle color choices
Fiddler Options dialog is now sizable
Added View Bytes option to Text Decoder applet
Fiddler now supports autohooking connection other than the default LAN connection
Fixed race condition in server socket pool

Version 1.0.1 - Released 8/30/05.

Fiddler will only load public, non-abstract types as Inspectors 
UI-tweak: Double-click in status bar panels to enable/disable capturing or set automatic breakpointing
Added Load Sessions option on File menu 
Added new flags request-trickle-delay and response-trickle-delay 
Fixed Windows Vista installation issue. Note Hex Inspector does not run on Windows Vista. 
Fixed startup code to show running instance if possible
New icons for 204/401/403/5xx/HEAD 
New color choices for Find results 
Prefaced all Fiddler-generated HTTP Response status lines with "Fiddler -" 
Added Spoof IE6 to default rules 
Updated so NTLM doesn't show "0" for second part of handshake. 
Added support for TextEditor registry key respected by the "View in Notepad" button on Standard::TextView 
Fixed JSEditor persistence on option screen 
Fixed duplicate accelerator on Options dialog

Version 1.0.0 - Released 7/7/05.

Restructured menus for clarity
Improved support for Windows Vista
Improved SSL CONNECT capture
Minor bugfixes

Version 0.9.9 - Released 2/1/05.

Fix to Chunked Transformer
Minor bugfixes

Version 0.9.8 - Released 12/29/04.

New scripting methods improve power
Scripting rules now stored in My Documents\Fiddler\Scripts
Header inspector improvements
Breakpoint experience cleanup
Improved Menu Extensibility via script
Assorted robustness improvements and bug fixes

Version 0.9.6 - Released 8/31/04.

Edit | Find now implemented
Scripting methods renamed for clarity; now stored in CustomRules.js
Text Encoder/Decoder no longer limited to one instance
Header Inspector now allows editing of >256 byte entries 
Header Inspector now breaks out cookies for easier reading 
CTRL+ALT+F systemwide hotkey
Menu Extensibility via script (see included script for examples) 
Better UTF8 support in XML Inspector
Assorted bug fixes

Version 0.9.5 - Released 6/24/04.

Copy Headers now works much better (no more junk like <!-- StartFragment-->) 
Dramatically improved NTLM rules handling (aka: rules now run) 
Header Inspector now allows editing
Supports OnBoot, OnShutdown, OnAttach, OnDetach in EventHandlers.js 
New x-fiddler-markitalic and x-fiddler-markstrikeout attributes for Session.Flags 
Assorted performance improvements 
Assorted bug fixes

Version 0.9.4 - Released 5/28/04.

Assorted bug fixes
New "Copy | Full Summary" feature to capture Sessions List data
Reorganized menus

Version 0.8.6 - Released 1/21/04.

JScript.NET auto-tampering rules and filters
Single-step debugging
Basic hand tampering now supported using TextView inspector only
Reorganized menus

Version 0.8.3 - Released 1/2/04.

Added SSL Tunneling
Added Chunked-Encoding
Added some basic spoofing options
Lowered memory consumption / increased speed
Reorganized menus

Version 0.8.2 - Released 10/26/03.

Added NTLM / Negotiate support
Fixed crash when an existing proxy erroneously prepended HTTP:// in IE Proxy Settings
HTTP Method / Response line more prominently displayed
Incremental Find Feature in TextView inspector
Download time approximations added to Statistics
Improved boot performance
Reorganized menus

Version 0.8 - Released 10/6/03.

Initial Release, supporting most viewing tasks


Fiddler Classic

Product Overview
Need Help?
Ask the Fiddler community
What's new across all Telerik products?
See the updates feed